P1ac Char . u, Lfiu: -1... t.b..lrl‘ {thriQO’nvv-b‘vrloiu- Littl.f.‘l):Lu.wEEL=‘b“t£-n. n: LEADING INDICATORS IN STRUCTURAL ECONOMETRIC MODELS WITH APPLICATIONS IN MULTIVARIATE TIME SERIES ANALYSIS ABOUT THE COMMERCE DEPARTMENT LEADING INDICATORS AND A PROPOSED MONETARY LEADING INDICATOR By Paul Koch A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Economics 1980 ”NOW/’7 ABSTRACT LEADING INDICATORS IN STRUCTURAL ECONOMETRIC MODELS WITH APPLICATIONS IN MULTIVARIATE TIME SERIES ANALYSIS ABOUT THE COMMERCE DEPARTMENT LEADING INDICATORS AND A PROPOSED MONETARY LEADING INDICATOR By Paul Koch The Commerce Department leading indicator approach has been criticized as being void of economic theory. In this study a leading indicator approach is formu- lated which is firmly embedded in an economic theoretical framework expressed as a dynamic, structural econometric model. A time series model in which leading indicators play a special role is derived directly from this structural model. In this context forecasts of the objective variable can be made with the current information provided by the leading indicator. The variance of the forecast errors can also be obtained in the analysis. The current state of the art of forecasting with econometric models uses the Final Form approach. The forecasting ability of this approach is compared with that of the proposed leading indicator approach. In light of the prOposed approach, the Commerce Paul Koch Department's leading indicators are evaluated. Bivariate1finm series models are built, describing the empirical relation— ships between economic activity and certain economic time series which the Commerce Department deems as useful leading indicators (components of their Composite Index of Leading Indicators). This examination reveals some possible flaws with the Commerce Department approach. Most of the Commerce Department leading indicators examined display no significant lead over economic activity. Furthermore, one of the few Commerce Department leading indicators which displays a considerable lead, is seen to have a relationship with economic activity that is contrary to the way it is employed by the Commerce Department. These flaws cast more doubt on the usefulness of the Commerce Department leading indicator approach, and possibly provide some insight as to why the approach has performed so poorly in the past. Finally, Money is considered as an alternative leading indicator. A multivariate time series model is developed, describing the empirical, dynamic relationship between Money and economic activity. This model is expanded at length to account for various problems with the sample period reviewed. The empirical results are discussed with their implications toward some considerations in Monetary Theory. To my family ACKNOWLEDGEMENTS I must first express my sincere gratitude to my thesis advisor, Robert H. Rasche, for his invaluable advice and guidance throughout this study. The time and effort which he generously gave has greatly promoted my under- standing of Monetary Theory. His insight has been instru- mental in solving the many problems which inevitably arise during any such project. I also wish to acknowledge the efforts of my guidance committee. James M. Johannes provided many helpful comments concerning exposition at all stages of the study. Peter Schmidt initially stimulated my interest in econometrics, and has provided helpful advice throughout my graduate career. Mark Ladenson also generously gave of his time in examining my work. It is also important to recognize my fellow graduate students at Michigan State University for their contributions on my behalf. Mike Thomson deserves special attention in this regard. Finally I would like to thank Terie Snyder for typing this tedious manuscript. ii TABLE OF CONTENTS List of Tables List of Figures. CHAPTER I II III INTRODUCTION LEADING INDICATORS IN STRUCTURAL ECONOMETRIC MODELS Introduction The Framework - - - . . Comparing the Relative Forecasting Abilities of the Final Form and the Proposed Leading Indicator Approach. . . . . . . . . The Final Form The Proposed Leading Indicator Approach Example 1 - - - - Example 2 FOOTNOTES. .......... APPENDIX 1: Fitting the Transfer Function in Equation (2.10) APPENDIX 2: A Useful Convention of Zellner and Palm - . . . - - THE PROBLEM OF SPECIFICATION ERROR Introduction . - A Discussion of the Problem FOOTNOTES . . . APPENDIX 3: Proof that Ordinary Least Squares Estimation Yields the Appropriate Estimate- - - iii Page vi \IE 13 13 18 26 35 51 57 62 66 67 71 73 TABLE OF CONTENTS (cont'd) CHAPTER IV AN EVALUATION OF THE COMMERCE DEPARTMENT LEADING INDICATORS. . . . . . Introduction . Critique of the Commerce Department Approach. . Empirical Evaluation Comparison With Beta Coefficients. Implications . Conclusions. V MONEY AS A LEADING INDICATOR Introduction Empirical Examination of the Relationship Between Money and Industrial Production . The Money Stock Data The Identification Stage Estimation of the Single Input Transfer Function . . . Expanding the Model to Account for the Energy Price Supply Shocks of the Early 1970's - BCD92. . . . The Identification Stage of Building the Two Input Transfer Function . . Estimating the Two Input Transfer Function . Implications of the Final Model. Expanding the Model to Account for the Energy Price Supply Shocks of the Early 1970's - Fuel Prices. . The Identification Stage The Estimation Stage . Implications of the Final Model. Expanding the Model to Account for Supply Shocks Due to Strikes in the Labor Force . . . . . . . . FOOTNOTES. . . . . . . . . . . . . VI CONCLUSION . . . . . . . . . . . . . . . . APPENDIX H: Data Sources. . . . . REFERENCES . . . . . . . . . . . . . . . . iv Page 75 75 77 81 103 10H 123 125 125 131 131 136 1U2 1H9 151 163 170 179 183 188 19k 198 20” 211 215 219 Table IV-1 IV-2 LIST OF TABLES Univariate Models for the Commerce Department Leading Indicators Bivariate Models for the Commerce Department Leading Indicators . . . . . . . . . . Money Stock Series — 1959 Cross Correlation Function: Prewhitened Money Stock and Industrial Production. . . . . . . Forecasting Industrial Production With Filtered Money Stock: l973.9-75.2. Cross Correlation Functions: Prewhitened Filtered Money Stock and BCD92. . . . . . . . Forecasting Industrial Production With Filtered Money Stock and BCD92: .1973.9-75.2. . . . Forecasting Industrial Production With Filtered Money Stock and BCD92: 1975.3-79.7. . Cross Correlation Functions: Prewhitened Filtered Money Stock and Fuel Prices. Forecasting Industrial Production With Filtered Money Stock and Fuel Prices: 1973.9-75.2. . Forecasting Industrial Production With Filtered Money Stock and Fuel Prices: 1975.3—79.10 Page 83 88 133 138 150 159 166 168 189 190 192 LIST OF FIGURES Figure “.1 Impulse Response Function: BCDl Average Workweek. “.2 Impulse Response Function: BCD3 Layoff Rate. ”.3 Impulse Response Function: BCD8 New Orders H.H Impulse Response Function: BCD19 Index of Stock Prices . . . . . . . . . . ”.5 Impulse Response Function: BCD29 Index of Housing Starts. . . . . . . M.6 Impulse Response Function: BCD32 Vendor Performance . . . ”.7 Impulse Response Function: BCD92 % Change in PPI . . . . . . . . . . . . . . ”.8 Impulse Response Function: BCDIOS Real Money Supply - Ml u.9 Impulse Response Function [Beta Coefficients]: BCDl. . . . . . . . . . . . . H.10 Impulse Response Function [Beta Coefficients]: BCD3. . . . . . . . . . . . . . . A.ll Impulse Response Function [Beta Coefficients]: BCD8. . . . . . . . . . . . . H.12 Impulse Response Function [Beta Coefficients]: BCD19 . . . . . . . . . . . . . . . . H.13 Impulse Response Function [Beta Coefficients]: BCD29 . . . . . . . . . . . . . . . . . . n.1u Impulse Response Function [Beta Coefficients]: BCD32 O C O O O O O O O O O O O O O O 4.15 Impulse Response Function [Beta Coefficients]: BCD92 . . . . . . . Page 95 96 97 98 99 100 101 102 105 107 109 117 LIST OF FIGURES (cont'd) Figure Page H.16 Impulse Response Function [Beta Coefficients]: BCD105. . . . . . . . . . . . . . . . . . . 119 5.1 Time Paths of Nominal Income and Its Components After a Monetary Shock , , , , , 129 5.2 Impulse Response Function: Prewhitened Money Stock and Industrial Production (Identification Stage). . . . . . . . . . . 190 5.3 Step Response Function: Prewhitened Money Stock and Industrial Production (Identification Stage). . . . . . . . . . . 193 5.9 Discontinuous Impulse Response Function - Filtered Money Stock . . , , , , , , , , 195 5.5 Continuous Impulse Response Function - Filtered Money Stock . . . , , , , . , , 196 5.6 Impulse and Step Response Functions Implied by Equation (5.27) - Money Stock. , 172 5.7 Impulse and Step Response Functions Implied by Equation(5.27) - BCD92 . . . . . 180 5.8 Impulse and Step Response Functions Implied by Equation (5.27)‘ - Money Stock . 195 5.9 Impulse and Step Response Functions Implied by Equation (5.27)‘ - Fuel Prices . 199 vii CHAPTER I INTRODUCTION With the advent of the Great Depression in the 1930's came the assigned task of the NBER of developing a leading indicator approach to forecasting, in the hope of helping to prevent another such catastrophe. Wesley Claire Mitchell and Arthur Burns collected data on various economic time series and set up criteria for choosing leading indicators from among these. Over the years the Commerce Department leading indicator approach has evolved into its present state, the current Composite Index of Leading Indicators (CLI). This approach has been criticized as being void of economic theory (Koopmans, 19u7). It is argued that theory should be used in choosing leading indicators, or the under- lying structural relationships are unknown, and thus the leading indicators cannot be used for policy decisions. Promoters of the Commerce Department approach have responded to this criticism by claiming that a theoretical foundation is present, since many of the series in the CLI reflect either direct or indirect measures of demand for various components of output, or reflect factors which have an impact on demand. In any case, it is further argued that if a method without underlying theory predicts better, then for certain uses it should be preferred. The record of the Commerce Department approach, however, has been less than satisfactory. The CLI has displayed two major faults: it has indicated many false downturns, and has displayed a highly variable lead time at true turns. These faults cast much doubt on the usefulness of this approach in the role of forecasting. This study develops a leading indicator approach which is built upon an economic theoretical foundation, as expressed in a dynamic, structural econometric model. Time series models in which leading indicators play a special role are derived directly from this theoretical framework. In this context, current observations of the leading indicators can be used to forecast the objective variable, and the variance of the forecast errors can be obtained. The current state of the art of forecasting uses the Final Form of an econometric model. The forecasting ability of this approach is compared with that of our leading indicator approach. Two examples are presented illustrating the approach, and this comparison of forecasting abilities. In light of our proposed leading indicator approach, we evaluate the Commerce Department leading indicators by building bivariate time series models describing the empirical relationships between the level of economic activity and eight of the components of the CLI. Five of the "leading indicators" examined display no significant lead over economic activity. The other three components exhibit the kind of relationships with economic activity that a good leading indicator is expected to have. However, the component which shows the greatest lead (the Producer Price Index of Crude Materials) is seen to have a negative rela- tionship with economic activity, while it is used in a positive role in the CLI. This analysis sheds light on some potential reasons for the poor record of the Commerce Department approach. Finally, Money is considered as an alternative leading indicator. The dynamic, empirical relationship between Money and real GNP is examined in the context of a multivariate time series model. The model is expanded to account for two kinds of supply shocks occurring in the sample period: the energy price shocks of the early 1970's, and strikes in the Labor Force. At all stages of its development, the model indicates a stable relationship between Money and real GNP, suggesting that Money may be quite useful in the role of leading indicator. CHAPTER II LEADING INDICATORS IN STRUCTURAL ECONOMETRIC MODELS Introduction A leading indicator can be defined loosely as an economic time series whose movements in some sense consist- ently lead economic activity. More formally, a leading indicator can be defined in the following context. We have some presumed knowledge of the joint distribution of Ipt+k and LIt’ f(IPt+k’LIt)’ where IPt+k = some measure of economic activity in period t+k (e.g. the index of industrial production), LIt = some leading indicator which we define, in period t. In period t we know the value of LIt' The leading indicator approach to forecasting suggests that we can use this knowledge of LIt to tell us more about the distribution of IPt+k’ Thus we are interested in: f(IP LI ) . _ t+k’ t This is the context in which leading indicators can be useful. We presumably know more about the distribution of IPt+k given LIt’ than without that information. That is, we can provide better forecasts of IP by using the condi- t+k tional distribution, f(IP' ILIt)’ than by using the t+k unconditional distribution, f k. t k l (t yAx {ll-Ill .«u ‘ ) L ( 2 1 H [Mall .fl .3 nun onul * l 1 .0 p m h l . W ) L ( *1 l H .21 .R1 1 co. _ .- ) k ( t y Ae ) L ( 2 l H .3 .8 .n» .«n can 1 ."n l l .p urn h l _ ) L ( .fl 1 l H .3 l .8 l 1 .0 p m h \'|ll|l b.“ t l t y X {I'll .3 .3 .8 ‘ ) J L ( 2 1 H .8 k *.l .81 .8 1 .31 on. p MW. mw l _ ‘ ) J L .( .81 l H .81 .81 1 0.0 p mm .W .... t 1 e .3 .3 ...» ‘l ) J L ( l 1 F l . ‘ ) J L ( .31 l H *1 t 1 1 1 on. p mm h- .... .... .K + t l e \I L ( 1 l P. ill.) ) L .( *1 l H .rl l l l .p h h i 22 lIIIIIJ IIKJIIJ t _ 1 ) R + Y k y t i _ (\ ...K X \J t t _ _ k l X +L .T. \l ( y A e l X ..L O +L {Ili y l X .n .. (IIIIIIK e A e ‘ L J 0.1 - r L t w J .m k t ...» l ) J4 L + l V I} e L ‘1 JJ t e W (\ \l l (\ \.I 2 ”w e .x L l 2 .«u I... H l .3 .fl 2 L J llllll H W i J ‘ L J l ) llllll ) ) H L .x .3 L L llllll (x .u .u l .n l (x ( .x l .8 l on“ 1 .3 l on“ 1 l 1 .fl .3 1 1 .a l . P .x l . P 1 l .x l .x 1 P h h h h F F .3 1 . P r L f L h h l l l l 1 r it . _ . _ _ l ‘ J \. J \I J N J W J — \J \l \l \l \I l L L L L L \l I.\ I.\ ...(\ ( I.\ L .r l .. l ... .1 .w l . l ( l l 1 1 l .3 l H H H H H l llllll H .n. 1 ... l ...: l .3 l .u. l .3 l l l .. l l . l l .3 ..l. l .3 1 l .8 l l l o o P o. l o p 1 p l o o p l p l o o P h hL ave rh hL an hL ,h hL rh hL h h It 1‘ t O r J L r J L r 11 IL r J L r {i ..D a _ _ . + _ — e Z __ h \J t k {\ g t n y .l A e y f .1 ) l 6 D. 2 m . Cl 2 S ( f :9: "l ‘ v f \ hll l I * L — f . IH11(L) F11(L) elt+k ,I I 1 LL pl | J J Observe that in this model, the forecast error of each endogenous variable is a function of the forecast errors of all inputs, and the noise associated with all pl endogenous variables occurring over the forecast period. Compare equation (2.26) with equation (2.20). Again, we wish to consider the variance of the forecast errors, given these assumptions: (i) the exogenous input series are mutually independent, (ii) each exogenous input is independent of each disturbance, and (iii) the model parameters are known with certainty. A A 2 Var[ey (k)] E[ey (k)] t t '"'. * w-lr *** a‘* h11 : h11 : 0 * '-' E “i : :H11(L) . :H12(L) ‘ ji— * *** ex k) L p1 I J p1 I J, rrh * w-l 1* _12 ll * -< . l H11(L) Fll(L)L e1t+k * h I LL p111 J J _‘ I. r 3': ‘-1r :'::'::‘: , 2 Ihll I hll I | g; . I 0 = B _, I IH11(L) I |H12(L) } ;*————- . *I h *v€*I ex (k) h I I t b J rrrh 3‘: | 1"]. .0. ’I2 11 ' ° I * (L) + B ‘ : {H11(L) F11 I elt+k a! I 1 LLL pl I J J J r I, a ,_1, *** ,‘a q I I h11 I h11 , 0 ' I ' I ______ = E _‘ . lHun.) : |H12(L) I A * *** e (k) h 1' h 1 I xt P P LLL ll J I 1 I ‘JI J fr! *| W-l \wi‘ hlll + I ' IH *(L) F (L) II E(e )2 I : . 11 11 lt+k * h I 1 LLLplI J J‘ [by (iii) above and our assumptions as to elt] Note that as before, double brackets around a matrix, {{ })*, refer to the transformation of the original matrix with single brackets, in which each element is squared. Again refer to footnote (12). Thus our forecast error variance finally reduces to the following: I I 2': , _ 1 :': :‘: :': 2 I F; 1 h11 ' H11 ' I a . I 0 = E -I : 'H11(L) : 'H12(L) I A h *I ***| ext(k) I I II P11: . I P11 I .J b I If * - :1: .12 rh I 1 1 11 I I * (L)I + . E I : :H11(L) F11 e1t+k * I I pll| J LI 1 J [by (ii) above] I Ifh * I 1-1rhfnka' I 1“" 'I 11 I * 11 I 0 ' I ’ I ______ = E -I : IH11(L) : IH12(L) I A * *fi* 3 (k) h 1' h 1 I xt P1 I P I fr * I -l H" hll I I + I ° IH *(L) F (L) II H(e )2 I : I 11 11 1t+k * h I II plll J I; [by (iii) above and our assumptions as to elt] Note that as before, double brackets around a matrix, {{ }}*, refer to the transformation of the original matrix with single brackets, in which each element is squared. Again refer to footnote (12). Thus our forecast error variance finally reduces to the following: I. r :‘t , _1 :'::'::‘: , ,‘c ‘2 Ih11 I Ih11 I , 0 A :‘z (2.27) V[e (k)] = IE -I : I (L) . III (L)I A O I 1 yt *I ll :‘cs‘n'cI ex (k) hp 1: hp 1 I t I. LL 1 I J I l I JJ .I p1x(p2+1) (P2+1)X1 (If k ‘_1 “« h11 : k + II : :H11(L) F11(L)II V(e1t+k) * h I l plxpl plxl In this context, the variance of the forecast error of aaah endogenous variable is a function of the variances of the forecast errors of all exogenous inputs, the appropriate covariances between forecast errors of different time horizons implied by ', * I‘lr *éé ,‘g h11 I , h11 I I I I IH11(L) : IH12(L) h *I h°***1 1| 1 I L I pl J I p1 J I (again see footnote (12)), and the variances of the disturbances associated with all endogenous variables. Compare equation (2.27) with equation (2.21). 26 Example 1 Consider an IS-LM model. Commodity Market ' : + + + (1) Ct a blYt—l b2rt—l elt : _ + + (2) It It bBPt—l e2t : + (3) Yt Ct It Money Market M? _ : + (u) Pt buYt-l bsrt-l + eat 5 - (5) Mt - MO + b6rt + eHt s _ d (6) Mt - Mt (7) Pt = Pt where Ct = consumption, It = investment, Yt = output, rt = "the" interest rate, P1: = commodity price level a = autonomous consumption, ft = autonomous investment and the e. are disturbances with E(e. ) = 0, 1t it B (e. e. = O and E(e. )2 = O. for i = l 2 3 u. 1t 3t 3 1t 1 9 3 3 ’ 9 i f j. The model consists of seven equations and seven unknowns: d Yt’ rt, Pt’ Mt’ M C and It' s t’ t’ Note thatcnu~dynamic formulation simply says each right hand side endogenous variable affects the left hand 27 side variable with a lag of one period, with one exception. The exception is the Money Supply equation. This equation reflects the likelihood that,banks will react quickly and efficiently in adjusting their excess reserve positions, in response to changes in the interest rate. I wish to assume that a Keynesian aggregate supply curve corresponds to this world. That is, assume: (i) whatever output is demanded can be produced, and (ii) Pt = Ft’ as expressed in equation (7). Note that we can express the system as two equations in two unknowns. These are the IS and LM relationships. IS: Yt = Ct + It = a + blthl + bZPt—l + e1t + It + bBPt-l + e21: .. : — + (7) (l blB) Yt a + It + (b2 b3)B rt + (e1t+e2t) where B = the backshift operator, or lag operator (previously specified as L). d - 5 LM Mt - Mt _ + _ _ : + bup Yt—l bsp rt—l + P eSt M0 be rt + eat (8) (—b6+b5PB) rt = M0 - buPB Yt + (eat-PeBt) Let elt+e2t - eSt’ and eat—Fe3t = eSt’ noting that E(e5t) = H(efit) = 0, and E(e5t-e6t) = 0. We now have two equations [(7) and (8)] in two unknowns: Yt and rt. This is the classic IS—LM problem, in 28 a linear structural model framework. The candidate for a leading indicator of Yt in this context is rt. Observe that rt affects Yt+l through its effect on Ct+l and It+ 1n the commodity market, and l affects Y through its effect on Yt+l’ which is involved t+2 1n the IS equation for Yt+2. Further, rt affects Yt+l through its effect on the LM relationship in period t+l. In short, rt is a factor in the determination of the locations of both the IS and LM relationships in period t+l. Consider equations (7) and (8) in matrix form. -(b2+b3)B (l—blB) rt a l 1 e51: II + (9) _ + _ — — ( b6 bSPB) buPB Yt M0 0 1t eBt This is our structural model with endogenous variables rt and Yt’- ourtransformation,vmflll.separate the polynomials in B and exogenous variable, It. Applying multiplying r into a component with lags, k < l, and a t, component with lags, k 3 l. O (l-blB) r (b2+b3)B a l r e t t 5t _ = _ l + -b6 buPB Yt -b5PB M0 0 ‘ft e6t or: 0 (l-blB) rt (b2+b3) a 1 Brt 'e5t _ = _ 1 + -b6 buPB Yt -b5P IQ) 0 I; IeSt P I Now we can solve for our endogenous variables, Y: , 29 Br 1: in terms of our predetermined variables, 1 .—1 It rt 0 (l—blB) (b2+b3) a 1 Brt : l Yt —b6 buPB J —b5P M0 0 It .-1 0 (l-blB) e5t + -b6 buPB , e6t -1 _ 0 (l-b B) b PB Substitute' l ' l u ' _ b6(l-blB7 --b6 buPB b6 rt 1 buPB -(l-bfn (b2+b3) a l = b l-bB 6 l — Yt b6 0 -b5P M0 0 1 buPB -(l-blB) e5t + b6 l-blB b6 0 e61: Multiplying through the matrices: I”t Yt [buPB(b2+b3)+b5P(l-blB)J [abuPB-MOU-blBfl 1 - b6(l 131—713 L b6(b2+b3) ab6 Br HI bPB‘ H 30 b PBe - (l-blB)e6t) This is the transfer function model implied by our dynamic structural system of simultaneous equations. Explicitly, the two transfer functions are: [b BB(b +b )+b F(l—b 8)] r1: = (const)r + u 2b (l bsB) l (Brt) t 6 ' 1 buBB _ + (I ) b6 l—blB t + 1 [b‘FBe - (l—b B)e J b6(l-blB) u 5t 1 6t b6(b2+b3) b6 _ Y : (CODSt) + fl (Br ) + j—T—y (I ) t Yt b6 1-bl t b6 1 blB t 1 + [b e J _ b6(l blB) 6 5t From the second transfer function, it is clear that Yt is a function of lagged values of our leading indicator, rt. Thus we can fit this transfer function for Yt’ and come up with the estimated mean and variance of Yt given past rt. And more importantly, we can come up with an estimate of Yt+1 given r That is, we can estimate the t. mean and variance of the conditional distribution,f(Y II‘ t+l t)° This is the object of our analysis of the leading indicator approach to forecasting. Consider the relative forecasting abilities of the Final Form (FF) approach and our leading indicator (LI) approach, in the context of example 1. 31 In the form of equation (2.”), we have: Hll(B) yt + H12(B) xt = Fll(B) e1t -(b2+b3)B (l—blB)- rt —a —l l e5t + : (-b6+b5PB) buPB Yt —M0 0 It e6t The Final Form: -1 .. + - rt (b2 b3)B (1 blB) a l l Yt (—b6+b5PB) buPB M0 0 It -(b +b )B (l-b B) ‘1 e 2 3 1 5t + (-b6+b5PB) buPB e6t Call the matrix to be inverted, A. - — 2 — det A — -buP(b2+b3)B + (l-blB)(b6—b5PB) = b - b FE — b b B + b b BB2 — b F(b +b )62 6 5 1 6 1 5 u 2 3 _ — — 2 — b6 — (b5P+blb6)B + F(ble-bq(b2+b3))B buPB -(l-blB) adjoint A = (be-bSPB) -(b2+b3)B A‘1 = _ buPB —(l—blB) 1 — — 2 b6-B c(l-B) (l-bBZ) 0 With this substitution, (10) becomes: ' 1 Vt ct = (ItJ r 2 2 3 2 1 r 1 d(B-B ) bd(B -B ) [l-ch+b(c-1)B J (6 a 0 th 1 2 1 b8 0 o 0 1 1 I I J I J d(B-B2) bd(Bz-B3) [l-ch+b(c-1)B2] elt‘ + 1 1 DB 0 e 1-ch+b(c—1)B2 2 2t c(l-B) (l-bB ) o e3t Multiplying out the coefficient matrices, and moving the determinant to the left hand side: Vt (11) [l-ch+b(c-1)B2] ct = IItJ rbd(B-62) ad(B-B2) bd(B2-B3)‘ 'th) b a b8 1 + Lbc(l-B) ac(l-B) (1-662) , LI NO (11) (cont'd.) r 1 _ + _ + — - delt-l delt-Z bde2t_2 bde2t_3 e3t bce3t_l+b(c l)83t-2 elt + be2t-1 _ + _ I celt ce1t-1 e2t be2t—2 I This is the transfer function model implied by our dynamic structural system of simultaneous equations. Our inputs are the leading indicator, V and the exogenous .t, variable, I Explicitly, the three transfer functions are: t. [l-ch+b(c—l)B2] Vt = (const)V + bd(B-B2)(BVt) t 2 3 — + bd(B -B )(It) + [delt-l - delt-2 + bde2t_2 - bde + e - bce + b(c-l) e ] 2t-3 3t 3t-l 3t—2 (12) [l-ch+b(c-1)B2] c = (const) + b(BV ) + 66(I ) t Ct t t 4. + [elt beZt-l] [l-ch+b(c-1)B2] It (const)I + bc(l-B)(BVt) t 2 _ + (l-bB )(It) + [ce1t - celt—l ] + e2t ' be2t-2 Finally, we can aggregate our transfer function models to yield the time series model for Y implied by our dynamic t, structural system of simultaneous equations. Lil From equation (5) we have: 4. Vt + It From this identity and the transfer function models for the components in (12), it is clear that Yt is a function of lagged values of our leading indicator, Vt' Hence, using time series methods, we can fit these transfer functions and come up with the estimated mean and variance of”Y given values of our leading indicator in t+l previous periods. That is, we can estimate the first two moments of the conditional distribution of Yt+1 given Vt’ f(Yt+l|Vt). This is the object of our analysis of the leading indicator approach to forecasting. With this knowledge we can produce optimal forecasts of Yt’ which are presumably better than forecasts produced without the incorporation of our knowledge of the structural relationships between our leading indicator and the other variables in our model. Consider the relative forecasting abilities of the Final Form approach and our leading indicator approach, in the context of example 2. In the form of equation (2.u), we have: U2 H11(B) yt + H12(B) xt = Fll(B) elt r-bB (l-bBZ) —bB‘ 'vt‘ ‘-a 0‘ 0 -c(l—B) 1 ct + o -1 2 1 —d(B—B ) 0 I 0 0 L I tJ \ J The Final Form: (Vt‘r-bB (l-bBQ) —bB"lfa 0‘ 1 ct: o —c(l-B) 1 o 1. It 2 I 1 —d(B-B ) 0 0 0 I tJ. J . J -bB (l-bB2) -bB ‘1 e lt + 0 - - c(l B) l e2t 2 1 —d - (B B ) 0 e3t Call the matrix to be inverted, A. det A adjoint A A-l l —_ det 1 e11: It : e2t .831“) (l-bB2) - bc(B—BZ) - bd(BQ-Bs) 2 2 + has 2 - ch + bCB l - b8 1 - ch + (be-b—bd)B2 + 666 rd(B-Bz) bd(Bz-Ba) : 1 13B c(l-B) (1-b62)-bd(62-B3 [adjoint A] + de3 3 ‘ (l-sz)-bc ( 6-62) bB ) bc(B~BZ) H3 Substituting this into the Final Form and moving the determinant to the left hand side, we get the following: Vt [det A] Ct = It d(B-Bz) bd(B2-B3) l—bB2-bc(B-BQ) a 0 1 = 1 bB b8 0 1 [— I I 2 2 3 2 t c(l-B) l—bB -bd(B -B ) bc(B-B ) 0 0 d(B-Bz) bd(BZ—B3) l-bBZ-bc(B-B2) e1t + 1 b8 bB e2t c(l-B) l-sz-bd(Bz-B3) bc(B-Bz) e3t Multiplying through the matrices: 2 2 3 1 Vt ad(B-B ) bd(B —B ) l [det A] Ct = a bB I 2 2 3 t It ac(l-B) l-bB -bd(B -B ), r 2 2 3 2 2 1 d(B-B )elt+bd(B -B )e2t+[l-bB -bc(B-B )]e3t + elt + bBe2t + bBe3t 2 2 3 2 c(l-B)elt+[l-bB -bd(B -B )]e2t+bc(B-B )e3t I J Consider each of the three Final Form transfer functions in turn. First; [l-ch+(bc-b-bd)B2+bd33] vt = (const)v t 2 3 — 2 2 3 + [bd(B -B ) [It] + d(B—B )e1t + bd(B -B )e2t 2 2 + [l-bB -bc(B-B )]e3t H3 Substituting this into the Final Form and moving the determinant to the left hand side, we get the following: , (Vt [det A] Ct = LItJ 'd(B-62) bd(BZ-B3) l—bBQ-bc(B—BQ)‘ a o 1 = 1 b8 bB o 1 [f I 2 2 3 2 t Lc(1-B) l-bB -bd(B -B ) bc(B-B ) J o o d(B-B2) bd(BZ-B3) l-bB2—bc(B-B2)‘ elt‘ + 1 bB bB e2t C(l-B) l-bBZ-bd(BZ-B3) bc(B-B2) 1 eat} Multiplying through the matrices: ’v ‘ 'ad(B-B2) bd(BZ-Bs> ‘ t l [det A] Ct 1' a 138 T 2 2 3 t LIt, Lac(1-B) l-bB -bd(B -B ), r 2 2 3 2 2 1 d(B-B )elt+bd(B -B )e2t+[l-bB -bc(B-B )Je3t + e1t + bBe2t + bBe3t 2 2 3 2 —bd(B -B )]e2t+bc(B-B )e3t Lc(l-B)elt+[l—bB J Consider each of the three Final Form transfer functions in turn. First; [l-ch+(bc-b—bd)82+bd83] vt = (const)v t 2 3 — 2 2 3 + [bd(B -B ) [It] + d(B—B )e1t + bd(B -B )e2t + [l-sz-bc(B-B2)]e3t U3 Substituting this into the Final Form and moving the determinant to the left hand side, we get the following: [det A] tJ 'd(B-B2) l LC(l-B) (d(B-BQ) l {C(l-B) Multiplying through the matrices: Vt C [det A] t LItJ _ + _ Lc(l B)e1t [1 b8 2 bd(Bz-B3) l—bBQ-bc(B-B2)‘ a 0‘ bB bB l-bBZ-bd(B2-B3) bc(B-B2) J bd(BZ—B3) l-bB2-bc(B—B2)‘ bB bB l-sz-bd(B2-B3) bc(B-B2) 1 ‘ (ad(B-B2) bd(B2-B3) ‘ 1 a bB [TI] 2 2 3 t Lac(l-B) l-bB -bd(B -B )J 'd(B-Bz)elt+bd(B2-BB)e2t+[l-sz-bc(B-B2)Je3t e1t + bBe2t + bBe3t 2 3 2 —bd(B —B )]e2t+bc(B-B )e3t [ ‘ J I l 1 t Consider each of the three Final Form transfer functions in turn. First; [l-ch+(bc-b—bd)Bz+bd83] vt + 2 + [l-bB 2 -bc(B-B )]e3t (const)v 2 3 — 2 [bd(B -B ) [It] + d(B-B )e1t + bd(B t 2 3 -B )e2t an (i) Vt = (const)vt + cht_l+(b+bd-bc)Vt_2--bdvt_3 + deIt_2] - bd[It_3]'t[delt_l-delt_2-+bde2t_2 - bde2t__3 + e3t - bce3,t_l + b(c—l)e3t_2] Second; [l-ch-t(bc-b-bd)B2+de3]Ct == (const)Ct+ bB[It] + elt + bBe2t + bBe3t (ii) ct = (const)Ct+-bcCt_14-(b+bd-bc)Ct_2-det_3-+b[I$€l] + [elt + be2t-l + best-1] Third; [I-ch+(bc-b-bd)62+de3]It==(const)It + [I-bB2 - bd(B2—B3)][I J + c(l-B)e t lt + [l—sz-bd(B2-B3)]e2t + bc(B—B2)e3t (iii) It == (const)It4-bclt_l+-(b+bd-bc)It_2-bdlt_3+'[It] - b(l+d)[It_2]+bd[It_3]+[celt—celt_l+e2t - 1 _ b(l+d,e2t_2+bde2t_3+bce3t_l bce3t_2] Note here that It is endogenous and If is exogenous. The aggregation of equations (i), (ii), and (iii) yields the Final Form transfer function of Yt Vt + Ut + It vt + ct_1-+It. This is done on the following page. H5 Yt = (const)Vt + cht_l + (b+bd—bc)Vt_2 - det—B + deft-Z] - bd[I£_3] + [delt-l-delt-Z + bde2t_2-bde2t_3 + e3t - bce3t_l + b(c-l)e3t_2] + (conSt)Ct-l + bcCt_2 + (b+bd-bc)Ct_3 — det-u + Mic-2J + [elt-l + be2t-2 + best-2J + (const)It + bCIt-l + (b+bd-bc)It_2 - det-B + [It] - b(l+d)[It_2] + deIt_3J + [celt—celt_l+e2t-b(l+d)e2t_2+bde2t_3+bce3t_l - bce3t_2] : (const) + bCEVt_1+Ct—2+It-l] + (b+bd—bc)[Vt_ +C +1 3 2 t_3 t_2]-bd[Vt_ +C +1 3 t-N t-3 + [It] + [celt+(l+d-c)elt_l-delt_2+e2t+e3t] (iv) Y (const) + bc[Yt_l] + (b+bd-bc)[Yt_2] - deYt-3] ... - + + + [It] [cel e e t 2t + (l+d-c)elt_ -de ] 3t 1 lt—2 Note that (const) = (const) + (const) + (const) . Vt Ct-l It Our initial assumptions as to these disturbances were: _ 2 _ 2 E(eit) - 0, E(eit) - Oi , H(eiteit-k and E(eitejt) = 0 for 1, 3=l,2,3 and 1 i 3. We see that the disturbance structure of our aggregation of' ) = 0 V k i 0, Yt is a second order autoregressive model about white noise. 1+6 From equation (iv) we get the Final Form forecast. Yt+l = (const) + bc[Yt] + (b+bd—bc)[Yt_l] - bd[Yt_2] + [Tt+l] + [celt+1+92t+1+e3t+l+(1+d-C)elt_delt-I] (v) 2t(l) = (const) tbCEYt]'t(b+bd-bc)[Yt_l]-bd[Yt_2] + [It(l)]+ (l+d-c)e1t - delt-l 2Yt(1) = §t(1) - Yt+l A ’ [It(l) ’ It+lJ ' ce1t+1 ' e2t+1 ‘ e3t+1 [eft(l)] — celJc+1 - e2t+1 - e3t+l A A 2 Var[e (1)] E[e (1)] Y1: Y‘t A 2 Var[eft(l)]+ c Var(elt+l)‘+Var(e2t+l) ) + Var(e3t+1 Now consider our leading indicator approach. Our leading indicator is V and we have our three transfer t3 functions from equation (12) in the example. Consider each in turn. First: [l-ch+b(c-1)B2]\Q: = (const)Vt + bd(B-BZ)[Vt_l] 2 3 — + bd(B -B )[It] + [delt_l-delt_2+bde2t_2-bde2t_3 + e3t - beeBt-l + b(c-l) €3t-2] U7 (V1) Vt = (const)Vt + bCVt-l -b(c-1)Vt_2 + bd(Vt_2] - bd[Vt_3] + bd[It_2] - bd[It_3] + [deit—1*“it-2 +bde2t_2-bde2t_3+e3t-bce3t_l+b(c-l)e3t_2] Second; [l-ch+b(c-1)B2] Ct = (const)Ct + bEVt-l] + bETt-l] + [elt+beZt-l] (vii) Ct = (const)C + bCCt-l — b(c—1)Ct_2 + bEVt-l] t + bEIt-l] + [elt+be2t_l] Third; [l-ch+b(c—l)82] It = (const)It + bc[Vt_l] - bc[Vt_2] + [If] - b[I£_2] + [celt-Celt-1+e2t-be2t-2] (viii) It = (const)I + bCIt-l - b(c-1)I,C__2 + bc[Vt_l] t - bc[Vt_2] + [It] -b[It_2] + [ce1t_celt—1+e2t - be ] 2t-2 The aggregation of equations (vi), (vii), and (viii) yields the transfer function for Yt implied by our leading indicator approach. (ix) H8 (const)Vt + bCVt-l - b(c-1)Vt_2-+bd[Vt_2] - bd[Vt_3] + bd[1t_2]-bd[lt_33'*[delt_1‘delt-2 + bde2t_2 - bde2t_3 + e3t - bce3t-1 + b(c—l) e3t_2] + (const)Ct-l'tbcCt_2-b(c—1)Ct_3'tb[Vt_2]'*b[T¥_fl + [elt-l + be2t-2] + (conSt)ItI+bCIt-l-b(C-1)It-24-bC[Vt-l]-bC[“F23 ] -ce +e -be lt-l 2t 2t-2 + [It] - tht_21 + [celt (const)+bc[Vt_l+Ct_2+It_l]--b(c-1)[Vt_2+Ct_3 + I ] + bc[Vt_l]+'b(l+d—c)[Vt_2]-bd[Vt_3] t-2 + [If] + bd[I£_ J - deIt_3]+-[celt 2 + (1+d-C)elt- -de 2+e + _ 1 lt- 2t bde2t-2 bde2t-3 J + e -bce + b(c-l)e 3t 3t-l 3t-2 (const) + bCYt- -b(c-1)Yt_ 'tbc[Vt_ ] l 2 l + b(l+d-c) [v ]-bd[Vt_3]+-[It]+-bd[It_ J t-2 2 - bd[1t_3] + [celt+82t+e3t] + [(l+d-c)elt_ -b ] 1 ce3t-1 + [-delt_2+bde2t_,&xc—1)e3t_2J+-[—bde2t_3] that (const) == (const)v + (const)C -+(const)I. t t-l t (ix) Y = Note that (const) = H8 - b(c—1)Vt_ -+bd[Vt_ J 2 (const)V + cht_ 2 t l — deVt_3] + bd[1t_2]-bd[1t_33'*[deit_1’de1t-2 + bde - bde + e - bce 2t-2 2t-3 3t 3t-l + b(c-l) e3t_2] + (const)ct_l-+bcct_2-b(c—1)ct_3-+b[vt_2]-+b[II;g + [elt-l + be2t-2] + (const)It'tbcIt_l--b(c-1)It_2 —be ] + ezt ‘CeIt-I 2t-2 + [It] - b[It_2] + [ce1t (const)'tbCEVt_1+Ct_2+It_l]-b(C-1)[Vt_2+ct_3 + I t_,] + bcEVt_l]4-b(1+d—c)[Vt_2]-bd[Vt_3] + [If] + deII_ J - bdliI't_3]-+[celt 2 -bde 'de 2t-2 2t-3 + + - (1 d Ckfitel 1t_2+e2t+bde ] + e3t‘bce3t-1 + b(C‘l)e3t-2 1 (const) + bCYt- -—b(c-1)Yt_ 4-bc[Vt_ l 2 l + b(1+d-c) [v ]-bd[Vt_3]+-[It]+-bd[It_ J t-2 2 + e3t] 1 +e - bd[1t_3] + [celt 2t -b + [(l+d-c)elt_l ce3t_l + [-de +bde +b(c-1ka ]'*[-bde J lt-2 3t-2 2t-3 + (const)C t t-l 2t-2 (const)V + bc[Vt_l] - bc[Vt_2] ‘+(const)I. t (ix) Y = Note that (const) == (const)V + (const)C +(const)I. H8 (const)Vt + bCVt-l - b(c-1)Vt_2+-bd[Vt_2] - deVt_3] + bd[1t_23-'bd[1t-3]'*[981t-1‘delt-2 + bde2t-2 ‘ bde2t-3 + e3t ’ bce3t-1 + b(c-l) e3t_2] + (conSt)ct_l'+bCCt-2"b(c_l)Ct-3'+b[Vt-2]'+b[jt49 + [elt-l + be2t—2] + (const)I 'tbcIt_l-b(c-l)It_2'tbc[Vt_l]-bC[fl}2] t 1 -ce +e —be + [It] ' b[It-2] + [Ge lt—l 2t 2t-2 lt (const)'tbc[Vt_l+Ct_2+It_l]-b(C-1)[Vt_2+ct_3 + It-2] + bc[Vt_l]4'b(l+d—c)[Vt_2]-bd[Vt_3] + [If] + deI£_2] - deI’t_3]-+[ce1t + + - - + - (l d exit-l delt-2+e2t bde2t_2 bde2t_3 + e -bce + b(c-l)e 3t 3t-l 3t-2J ] (const) + bCYt— -b(c-1)Yt_ 4-bc[Vt_ l 2 l + b(l+d-c) [vt_2]-bd[vt_3]+-[It]+-bd[It_2] - deIt_3] + [celt+82t+83t] + [(l+d-c)elt_ -b J 1 ce3t-1 + [-de +bde +b(c-lk3 ]'t[-bde ] lt-2 2t-2 3t-2 2t-3 t t-l t H9 Also, given our assumptions regarding the disturbances, eit’ the noise structure of Yt is seen to be a third order auto- regressive scheme. From equation (ix) we get the forecast of our leading indicator approach. (x) t+l Yt(l) ) (l Varfe ) Y +-bde t (1)] (const) + cht - b(c-l) Y + bCEVt] t-l b(l+d-c)[Vt_ J — devt_2] + [Ith + deIt_ I l l bd[It_2] + [celt+l+e2t+l+e3t+l] [(l+d-c)elt-bce3t] + [—delt-l+bde2t-l b(C—l)e3t-l] + [-bde ] 2t-2 (const) + cht-b(c-1)Y -+bc[Vt] t-l b(l+d-c)[Vt_ J - bd[Vt_2] + [It(1X1+ deIt_ ] l l deIt_2] + [(l+d-c)elt-bce3t] + [-delt?1 +b(c—l)e3t_1] + [-bde ] 2t-l 2t—2 Yt(l) - Yt+l [It(l) - It+l]'+[celt+l+e2t+1+e3t+1] [ef£(l)] + [celt+1+e2t+l+e3t+l] HEY (1)]2 t A 2 Var[eft(1)]‘I c Var[e1t+l]'+Var[e2t+l] Varfe3t+l] ... Also, given our assumptions regarding the disturbances, us e 0 1t’ the noise structure of Yt is seen to be a third order auto- regressive scheme. From equation (ix) we get the forecast of our leading indicator approach. (x) t+l Yt(1) > Var[e (1) Y +bde2t_l +b(C-l)e3t-l] + [-bde t (1)] (const) + cht - b(c—l) Y + bc[Vt] t-l b(l+d-c)[Vt_l] - deVt_2] + [It+g + deIt_ 3 l bd[It_2] + [celt+l+e2t+l+63t+l] [(1+d-c)elt—bce3t] + [-delt-l+bde2t—l b(C-l)e3t-l] + [-bde ] 2t-2 (const) + cht-b(c-1)Y ~+bc[Vt] t-l A b(l+d-c)[Vt_ J - deVt_2] + [It(lfl + deIt_ I l l deIt_2] + [(l+d—c)elt-bce3t] + [-deltvl 2t-2:I Yt(1) - Yt+l [It(l) ' It+l“[ce1t+1+e2t+1+e3t+1J [2f (1)] + [ce ] t lt+l+82t+l+e3t+l E[e 2 (1)] Yt VarEQT (1)]4-c2VarEe ]'+Var[e ] t + Var[e3t+l] lt+l 2t+l H9 Also, given our assumptions regarding the disturbances, eit’ the noise structure of Y is seen to be a third order auto- t regressive scheme. From equation (ix) we get the forecast of our leading indicator approach. (x) t+l Yt(l) ) (l Var[e ) Y -+bde t (1)] (const) + cht — b(c—l) Y + bc[Vt] t-l b(l+d-c)[Vt_ J - .bd[vt_23 + [I£+g + deIt_ 3 l 1 deIt_2] + [ce ] ' + lt+l+e2t+l e3t+1 [(1+d—c)elt-bce3t] + [-delt_l+bde2t_l b(c-l)e3t_l] + [—bde J 2t-2 (const) + cht-b(c-1)Y -*bc[Vt] t-l b(l+d-c)[Vt_ l] - bd[Vt_2] + [It(1xl+ deIt_l] deIt_2] + [(l+d—c)elt-bce3t] + [-deltvl +b(C-l)eBt-l] + [-bde ] 2t-l 2t-2 Yt(l) - Yt+l [It(l) - It+l].+[celt+l+92t+l+83t+l] [ef£(1)] + [celt+l+e2t+1+83t+1] BE;Y (1)]2 t J ]'+Var[e VarEeT (l)]+'c2Var[e t Var[e3t+l] lt+l 2t+l .... 50 Note that the one step ahead forecast error for the leading indicator approach is identical with that of the Final Form approach. Hence we have outlined an approach with an explicit theoretical background in which leading indicators can be studied and used, and which performs as well as the Final Form approach. It is not surprising that the two approaches yield the same forecast errors for forecasts within the horizon of our leading indicators' lead. They are obtained from essentially the same information set. They are just different algebraic manipulations of the same model. 51 FOOTNOTES CHAPTER II Box and Jenkins, Time Series Analysis, Holden Day, Inc., 1977, pp. HOH-HlO. Evans, M.K., Macroeconomic Activity, New York: Harper and Row, 1969, Chapter 16. The Handbook of Cyclical Indicators, A Supplement to the BCD, May,l977, pp. 170-185. Evans, op. cit. Koopmans, T.C., "Measurement Without Theory," Review of Economics and Statistics, August919H7. Vining, R., "KOOpmans on the Choice of Variables to be Studied and of Methods of Measurement," Review of Economics and Statistics, May,19H9. Harris,I%JV.and Jamroz, D., "Evaluating the Leading Indicators," Monthly Review of the Federal Reserve Bank of New York, June,1976. Zellner and Palm, "Time Series Analysis and Simultaneous Equation Econometric Systems," Journal of Econometrics, 2, 197H, pp. l7-5H. Theil and Boot, "The Final Form of Econometric Equation Systems," Review of the International Statistical Institute, Volume 30:2; 1962, pp. 136-152. 0Box and Jenkins, op. cit. Box and Jenkins, op. cit., p. HOH. Well known fact: If Zt is a vector of mutually independent random variables with E(zt) = O and E(zt zt-i) = 0, i = 1,2, ... , and if H is a matrix with known coefficients, 52 then Var{[H]zt} = E{[H]zt}2 = [[311 Var(zt); where [[H]] is the transformation of [H] made by squaring each element in [H]. A simple example: Let 1 -2 e llt [H] : ; zt : 3 0 e21t with the e's having properties identical to those in examplel. 1 -2 ellt Var{[H]zt} = Var 1 I I 3 0 e211; First, with our Second, the straightforward transformation; development; 1 u e11t e11t'2821t = Var = Var 9 0 e21t 3e11t + .. Var(ellt) HVar(e21t) Var [ellt 2e21t] 9Var(ellt) Var[3e11t] Var(ellt)+HVar(e21t) 9Var(ellt) It should be noted that in our model, each element in [H] is a polynomial in L, the lag operator. In this context, to transform [H] into [[H]] we need to square the coefficient of each different power of L appearing in every polynomial comprising an element in [H]. 53 A less simple example: Let (B-3B2) 2B2 ellt [H] = 3B3 0 ; zt = e 21t I B—3B2 2B2 e ‘ llt Var{[H]zt} = Var 1 3 I I 3B O e2lt J First, with our transformation; 2 2 2 2 2 (1) B+(-3) B (2) B ellt : V 2 3 (3) B 0 ezlt 2 2 (B+QB ) HB ellt = V 3 9B 0 eth ' BV(e )+9B2V(e )+HB2V(e ) llt llt 21t 3 I 9B V(ellt) ' + V xt o I o I h a" h :‘c:'::':l . P 1 J . P 1 J I l 1 J10- I 9 1"]. ‘ Ih11 I I 1121:: : + 3': ' Z lHll (L) Fll(L)) e1t ' l h 3': I 1 I. p, J J1. Note that this vector multiplying xt is the same vector as in (2.11), without the first element, g(L). This can now be solved for ylt: r 2’: ‘-l[ :‘:':‘: “ h11 I h11 "I 2': :‘n’n‘: h21 I h21 I (2.13) ylt = -(1+g(L)Lk)‘1< : .Hll='=(L) : IH12‘L’ )xt . I . I h :‘al h :‘fil \L p11 J I p11 J11“- r 1 f 1-1 h11 I k -1 h21* ' + (1 + g(L)L ) J . Hll*(L) F11(L)) e1t 1 l h. " This gives us the transfer function for our leading indicator, ylt’ implied by our structural model, in terms of exogenous 60 variables only. This can be fitted by prewhitening the input, substituting [H22_1(L) F22(L) €2t] for xt: (2.1a) y1t = —(1+g(L)Lk)‘1I I [H22‘1(L> F22(L)e2t] 10— + (1+g(L)Lk)'l I I elt 1. - - Lk ylt We can now substitute this model for y into x *== —————— lt t xt Hence we have X * entirely prewhitened, and can now work t with our model for the measure of economic activity in (2.10): - k k -1 -1 I [‘L (1+8(L)L ) {}1._H22 (L)F22(L)e2t * + Lk(1+g(L)Lk)‘lI} e I Xt = 1. 1t -1 H22(L) F22(L) e2t rrh ":l l-lfh '.'.J. I I‘ 11 I 11 I a fi‘* I h21 I h21 I I . (2.10) y2t - - : IHll«(L) : [H12(L) [Xt"I ' I ' I h *I h "* I 1 1 LL Pl I J L pl I 1J2. r! .3. "'l W hlldb : I h21 I * + . I H11 (L) F11(L)+ e1t ' I *l J J2. I 61 Note that equation (2.13) is the same equation as is implied in the structural system in equation (2.”). The Final Form for the system is: _ -1 -l (2.15) yt - -H11(L) H12(L) x + H11(L) F11(L) e t 11: The first equation of the Final Form is the same as equation (2.13). APPENDIX 2 A USEFUL CONVENTION OF ZELLNER AND PALM APPENDIX 2 A USEFUL CONVENTION OF ZELLNER AND PALM At this point let me interject a useful convention which Zellner and Palm point out, when working with this kind of model transformation (see footnote 8). In both the Final Form and leading indicator approaches, our model is expressed as a vector of endogenous variables in terms of a set of linear combinations of predetermined variables and disturbances, in a dynamic framework. In matrix form, our coefficient matrix is the product of two known matrices (say A and B), one of which is in inverse form. That is, our model is of the form; yt = [A'1131xt + [A—lCJet. From our presumed knowledge of A, B, and C, we can compute A-1 = HE%—A [adjoint A], and thus we know [A—lB] and [A—lC]. Note that in our context, each element of [A-lB] will be the ratio of two polynomials in L, with the denominator being the determinant of A; i.e. [A-lB] = 35%f3 [adj A][B]. A distributed lag which is the ratio of two polynomials in L implies a lag of infinite order. Hence we have a quite complicated system. We can simplify this system by multiplying both sides 62 63 of the equation of our model by [det A]; i.e. [det Aly,C = [adj A][B]Xt + [adj A][C]et Here our system is in the form of a transfer function with current and lagged yt's in terms of current and lagged xt's and disturbances. An interesting aspect of this system is that the order and parameters of the autoregressive part of each equation will be the same. This is true because the determinant multiplying the vector, yt, is a single polynomial in L. Note that with this manipulation of our models, equations (2.16), (2.17), (2.23), and (2.2”) will be changed as follows. Final Form approach; (2.16)‘ det[Hll(L)] yt+k —[adj H11(L)][H12(L)] x t+k +[adj H11(L)][F11(L)] elt+k -[adj H11(L)][Hl2(L)] xt(k) (2.17)' det[Hll(L)]yt(k) + {[adj H11(L)][F11(L)J}***e1t Leading Indicator approach; h11* l ' ' I :': : (2.23) det : I Hll (L) yt+k h *, p11 6H f f WI :': ‘ r ‘ hll J . 11 I y = _J . . . lt adj : I H11 (L) I :H12(L) I x * . t+k h I J h '*I J L l k f (h :1 W ‘ 11 I +4 ' : I 2': adj . I H11 (L) F11(L)I elt+k Rh ' I hllz: I ' ° :': _ (2.2M) det I I H11 (L) yt(k).. h ' p11 ' f {h ' I ‘ Ih u I 1‘ 11 I 11 l y :_ J . . * . 1t adj : I H11 (L) : [H12(L) I A h .I h ...I xt(k) L L p11 J L p11 J J I Ih . ‘ 11 I + ' 2': Jad] : J Hll (L) F11(L)> e1t h *I L L P11 J In this form the forecasts of yt(k) in equations (2.17)' and (2.2M)‘ will not only be in terms of the history and forecast profile of Xt’ but will also depend on the past history and forecast profile of yt itself. This is due to the determinant multiplying the vector of endogenous variables. Furthermore, the autoregressive part of all of the pl forecasts in yt(k) will be identical. The presence of these "lagged" forecasts of yt will 65 cause complications when we consider the variance of the forecast errors, since forecasts of yt(l), yt(2), ... , yt(k-l) will be correlated with each other, with forecasts of xt(l), Xt(2)’ ... , Xt(k)’ and w1th elt' This is obvious in the examples, in which this convention is used. CHAPTER III THE PROBLEM OF SPECIFICATION ERROR Introduction In Chapter II we proposed a framework for studying and using leading indicators. We outlined a procedure for building transfer function models by setting up a structural model, and deriving the time series models directly from this explicit theoretical background. In Chapters IV and V we will consider multivariate time series models which describe various empirical relation- ships between "established" leading indicators and economic activity. We will build the transfer functions empirically by following the procedures outlined in Box and Jenkins' Time Series Analysis.1 This procedure is chosen over the framework formulated in Chapter II. The transfer functions we examine in Chapter IV consist of economic activity (Industrial Production) as the output, and as a single input, the leading indicator under consideration.. In light of Chapter II, it may be argued that there is an econometric problem of omitted variables in this approach. At the outset, our single—input transfer functions will appear to reflect a belief that the level of economic activity is adequately "explained" by the use of just one RR 67 input. The framework in Chapter II shows that the number of inputs in the transfer function implied by any given econo- metric model will be equal to the number of exogenous vari- ables plus the number of leading indicators in that model. Even the simplest structural econometric model will imply a transfer function with more than one input. It is important to emphasize that our work is not done with the presumption that a single input is sufficient to explain the movements in economic activity. We follow the Box and Jenkins procedure because we are interested in the dynamic relationships which exist empirically between economic activity and each of the leading indicators under consideration. Furthermore we argue in this chapter that the bias introduced in the parameter estimates of our single input transfer functions through the omission of variables, does not present a serious problem.:tfthe following conditions characterize the model being studied. (i) The main objective of building the modeliésforecasting. (ii) The variables in the underlying econometric model are drawn from a joint distribution which is covariance stationary. A Discussion of the Problem Suppose that the true model describing the world we are examining is : +...+ 1’ (3'1) yt lelt + B2X2t BKth et 68 or (3.2) Y = X8 + e where Y is a Txl vector of observations on the endogenous variable, expressed as deviations from the mean; X is a TxK matrix of explanatory variables expressed as deviations from their respective means, which are drawn from a multivariate Normal distribution2; B iSéinl vector of true model parameters; and 2 8 iSéiTxl vector of disturbances, with €%N[0,0 IT]. We use only Xlt' Thus (3.3) E(yt|xlt) = lelt + B2E(x2t|xlt) + ... + BKE(th|xlt) Under our assumptions, 0 - 12 - E("2tlxlt) ' "E Xlt ' C2Xlt o l o _ l3 _ H(XBtIXlt) ‘ 2 Xlt ” C3Xlt o l (3.”) o _ 1K - E (l-B12)(l-B)log(zt) = (l-.21188)(1v.82089812)at (.05) (.033) X28 = 3u.7 RSE = .007u —2 (RSE)2 ( 007H)2 R = 1 "' 7-2—— = 1 " ‘ 2 = .1457” Goutput (.0100H6) where o is the standard error of output (1-812)(l-B)log(zt). BCD3: Layoff Rate Sample: 19H7 — August, 1979: n = 392. 12 (u.2) (l-Bl2)(l-B)log(zt) = <1-.710953 ) at (.037) 2 _ _ x29 - 33.5 RSE — .167H —2 ( 167H)2 R = l n '° .3157 (.20236)2 8H TABLE IV—l (cont'd.) BCD8: Value of Manufacturers‘ New Orders Sample: 1958 ~ May, 1979: n = 257 (0.3) (l-Blz)(l-B)log(zt) = (1..09590312)at (.0H8) 2 _ _ x29 — 26.3 RSE - .0355 —2 < 0350)2 R = l - ' 2 = .3107 (.0H2878) BCD19: Index of Stock Prices Sample: 19H? - October, 1979: n = 39H. (0.0) (l-.2186B)(l-Bl2)(l-B) log(zt) = (l—.8216Bl2)at (.051) (.030) X28 2 30.7 RSE = .0353 —2 ( 0353)2 R = 1 — ' 2 = .0113 (.0H6007) BCD29: Index of Housing Starts Sample: 1959 — August, 1979: n = 2H8. (0.5) (1-B12)(1-B)log(zt) = (l-.2H912B+.30H7882 (.005) (.007) + .19372135 — .5952512)at (.0H5) (.0H8) 2 - _ X26 _ 07.1 RSE - .0895 —2 ( 0895)2 R = 1 - ‘ = .3529 (.11213)2 85 TABLE IV-l (cont'd.) BCD32: Vendor Performance Sample: 19H7 — October, 1979: n = 39H. (0.6) (l-.2992B + .069287 + .1559B1u)(l-B12Xer)log(z ) (.050) (.050) (.008) t = (1—.6600812)at (.0H0) 2 x = z 26 39.2 RSE .125 —2 ( 125)2 R = l — ° = .H725 (.17211)2 BCD92: Percent Change in PPI of Crude Materials Sample: February, l9H7 - August, 1979: n = 391. (0.7) (l-.3756B — .2H0583)(l-812)(l-B) log(zt) (.0H9) (.0H6) = (l-.1H68B2 — .7331812 + .099Blu)at (.056) (.037) (.055) X2 = 38.5 RSE = .0157 2 R2 = l _ (.0157) 2 : .H732 (.021631) BCD105: Real Money Supply (Ml) Sample: 19H? - September, 1979: n = 393. (0.8) (l-.20358)(l-812)(1-B) log(zt) (.052) = (1 + .1905883 _ .56297812)at (.003) (.000) 2 x = = 27 33.0 RSE .0059 2 R2 = 1 _ (.0059) = .2936 (.00702)2 86 Two mild exceptions to the stability described above appear in the models for Housing Starts (BCD29) and Producer Prices (BCD92). Observe that these models are more complicated than the surprisingly simple models which describe the other leading indicators. The problem with both of these series is that the model parameter estimates vary somewhat more in the subsamples. Though some of the parameter estimates remain within one standard deviation of the estimate for the entire sample, others move outside this band of one standard deviation, and a few move outside the (23) confidence band. However, both of these models have the redeeming qualities that the X2 statistics and the RSE's are quite robust, and the SSE‘s for the subsamples constitute close to 50% of the SSE for the entire sample. Furthermore, the £23m of each of these models remains appropriate in all subsamples considered. It is not surprising that these two models are the least stable. Housing starts have been subject to the whims of Regulation Q enforcement; and the PPI since 1973 has been subject to some degree to the whims of OPEC pricing. In light of these facts, it is remarkable that these series behave as well as they do. The extent of the stability of these eight models is fairly amazing, given their simplicity, the length of the sample period, and the volatility of many of the leading indicator series. With these univariate models established, we can 87 examine the cross-correlation function between the pre— whitened input and the prewhitened output of each of our eight transfer functions. In so doing we obtain information about the form of the transfer functions under considera- tion. With this information, we proceed to the estimation stage and finish building our eight models, which are displayed as equations (H.9) through (H.16) in Table IVw2. To examine the stability of these models, we split the sample of each into two relatively equal subsamples and re-estimate. The resulting parameter estimates appear directly beneath those for the entire sample, for each of our eight models in Table IV—2. Examination of the parav meter estimates of these subsamples indicates that our models are quite stable. A study of the diagnostic checks for each model supports this finding. We conclude that the models adequately represent the bivariate relationships between each of the eight leading indicators under consideration and Industrial Production. We are interested in the impulse response function implied by each of our models. These eight functions are listed and plotted in Figures (H.l) through (H.8). We would like to compare these eight functions in order to make some evaluation about the strengths and weaknesses of each in the role of leading indicator. However since the inputs are not all measured in the same units, and since each input behaves differently (in particular, since each input has a different standard error), this comparison 88 TABLE IV—2 BIVARIATE MODELS FOR THE COMMERCE DEPARTMENT LEADING INDICATORS yt = BCDH7 Index of Industrial Production (i) xt = BCDI: Average Workweek Sample: January, l9H7 — September, 1979 (n: 393) 12 mo 12 (H.9) (l-B )(l-B)log(yt) I:EI§ (l-B )(l—B)log(xt) 12 + (1-812B )at w = 1.0260 61 = .6777 012 = .7H62 O (.079) (.036) (.035) 2 _ - x”, — 60.7 R58 _ .0117 r 2 1 R2 = l _ AéRSE) 0output 2 = l _ (.0117) 2 : .652H L (.0198H6) , Sample: January, 19H7 — April, 1963 (n = 196) w = 1.2599 61 = .6098 012 = .7670 (.133) (.056) (.053) 2 - _ x“, — 00.0 RSE — .0136 —2 ( 0136)2 R = l — ° = .530H (.0198H6)2 89 TABLE IV—2 (cont'd.) Sample: May, 1963 — September, 1979 (n = 197) mo = .7093 51 = .7099 812 = .7012 (.092) (.008) (.055) x37 = 57.8 R58 = .0096 —2 ( 0096)2 R : l — ° 2 3 .7660 (.019805) (ii) xt = BCD3 Layoff Rate Sample: January, l9H7 - August, 1979 (n = 392) w -w B (0.10) (l-Blz)(l-B)log(y ) = —O—l—(l-B12)(l-B)log(x ) t 2 t 1-62B 12 + (1-012B )at w = -.0300 ml = 0315 52 = .5927 912 = .7565 O (.003) ( 003) (.005) (.035) x37 - 56.0 RSE = .0116 R2 = .6580 Sample: January, 19H? - April, 1963 (n = 196) w = -.0381 w = .0331 5 = .5569 e = .7609 O (.005) l (.005) 2 (.065) 12 (.053) X07 = 08.5 R58 = .0139 R2 = .5090 Sample: May, 1963 - August, 1979 (n = 196) w =-.0299 ml = .0261 52 = .6597 912 = .7095 (.00H) (.00H) (.062) (.058) X07 2 02.9 R58 = .0096 R2 = .7660 90 TABLE IV-2 (cont'd.) (iii) (0.11) (iv) (H.12) xt = BCD8 Value of Manufacturers' New Orders Sample: January, 1958 - May, 1979 (n = 257) w -w B (1-812)(l-B)log(y ) = —9—4l— (1-812)(l-B)log(x ) ‘t 2 ‘t 1-62B 12 + (1-8128 )at w = .2396 w = —.0865 6 = .3H71 0 = .695H 0 (.019) l (.018) 2 (.062) 12 (.009) x39 = 39.1 R58 = .0103 R2 = .7306 Sample: January, 1958 - December, 1969 (n = lHH) w = .2306 ml 3 -.0731 62 = .3175 012 = .6H9H (.027) (.026) (.102) (.072) x39 = 02.2 R58 = .0116 R2 = .5580 Sample: January, 1970 - May, 1979 (n 113) w = .2616 ml = -.102H 62 = .3852 012 = .7353 (.026) (.025) (.076) (.079) x39 = 25.2 R58 = .0091 R2 = .7897 Xt = BCD19 Index of Stock Prices Sample: January,l9H7 - October, 1979 (n = 39H) (1-812)(1-B)log(y ) = ——9——82(1—812)<1-8)1og(x ) t 1-618 t 1-0 B12 + 12 a l-¢lB t w = .0670 51 = .8155 812 = .7902 *1 = .2739 (.015) (.059) (.032) (.051) x35 = ”5.6 R58 = .0132 R2 = .0020 91 TABLE IV-2 (cont'd.) (v) (0.13) Sample January, 1907 - May, 1963 (n = 197) 6 = .0961 31 = .6903 812 = .8007 $1 = .2931 (.031) (.101) (.006) (.070) 2 _ _ X06 35.8 R58 — .0159 R2 = .3581 Sample: June, 1963 - October, 1979 (n = 197) w = .0537 5 = .8919 8 = .7830 g = .1831 O (.012) l (.036) 12 (.051) l (.076) 2 _ _ X06 38.5 R58 — .0103 R2 = .7306 xt = BCD29 Index of Housing Starts Sample: January, 1959 - August, 1979 (n = 208) (l-Blz)(l—B)log(yt) 2 wOB9(1-Bl )(l—B)log(xt) 1-8 812 + 12 at l—¢lB w = .0172 812 = .5908 *1 = .3797 (.007) (.056) (.050) X06 = 37.2 R58 = .0120 I R2 - .6096 Sample: January, 1959 - April 1969 (n = 120) w = .0278 012 = .0052 61 = .2569 (.012) (.09H) (.100) 2 _ _ XL,6 — 32.7 RSE - .0130 R2 = .5001 92 TABLE IV-2 (cont'd.) (vi) (0.10) Sample: May, 1969 - August,l979 (n = 120) A A A w = .0125 612 : .6539 $1 = .5031 (.096) (.082) (.090) 2 _ _ X06 — 39.0 R58 - .0121 R2 = .6283 xt = BCD32 Vendor Performance Sample: January, 1907 - October,l979 (n = 390) (L) (1-812)(l-B)log(y ) = ~—9—— 82(1—812)(1—B)log(x ) t 1-618 t 1—0 812 + _11121__ 1-¢ B at 1 w = .0180 61 = .7551 912 = .7811 ¢1 = .2770 (.000) (.078) (.033) (.052) x36 = 05.0 R58 2 .0133 R2 = .5509 Sample: January, 1907 - May, 1963 (n = 197) w = .0163 61 = .8625 912 = .8061 ¢3 = .2800 (.005) (.072) (.050) (.070) 2 _ - x£46 - 30.9 R58 - .0160 R2 = .3500 Sample: June, 1963 - October, 1979 (n = 197) 0) = .0279 §_= .0870 812 = .7775 01 = .2138 (.008) (.176) (.051) (.079) 2 _ - X06 - 03.2 R58 - .0105 R‘ = .7107 93 TABLE IV—2 (cont'd.) (vii) xt = BCD92 % Change in PPI of Crude Materials Sample: January, 19H? - August,l979 (n = 392) 12 1-9 B 12 _ mo 10 12 12 (14.15) (l-B )(l-B)log(yt) - ITO? B (1-B )[Xt]+ 1—¢1B at w =‘.1062 51 = .7792 912 = .77H7 $1 = .2886 (.033) (.083) (.030) ( 051) 2 _ _ X06 — 37.7 RSE - .0136 R2 = .5300 Sample: January, 1907 - April, 1963 (n = 196) w = -.0700 61 = .8596 612 = .8051 91 = .3101 (.000) (.096) (.052) (.070) 2 _ _ X05 - 30.5 RSE - .0168 R2 = .2830 Sample: May, 1963 - August, 1979 (n = 196) A A A w = -.1965 6 = .5052 8 = .6689 0 = .1595 O (.009) 1 (.105) 12 (.060) l (.079) 2 _ - . X06 - 00.7 R58 — .0107 R2 = .7093 (viii) xt = BCD105 Real Money Supply - M1 Sample: January, 1907 - September, 1979 (n = 393) (L) (0.16) (1-812)(1-B)log(y ) = —°— 85(1-812)(1—B)log(x ) t 1-618 t 1-812812 + ———————— a 1-018 t Q = .3267 31 = .6511 612 = .7960 ¢1 = .3029 (.109) (.153) (.033) (.050) 2 _ _ X05 - 06.8 R58 - .0136 R = .530H 90 TABLE IV-2 (cont'd.) Sample: January 1907 - May, 1963 (n = 197) w = .3055 01 = .5018 012 = .8055 01 = .3717 (.177) (.333) (.008) (.072) X36 = 36.8 R58 = .0160 R2 = .3171 Sample: June, 1963 — September, 1979 (n = 196) w = .3378 6 = .7123 0 = .6881 ¢l = .2578 O (.103) l (.151) 12 (.059) (.076) 2 _ - _ X06 - 35.5 R58 - .0111 —2 R = .6872 xt 95 FIGURE 0.1 GRAPH OF IMPULSE RESPONSE WEIGHTS [vk] = BCDl Average Workweek 0. .25 .5 .75 l. (k) +++++++++.+++++++++.+++++++++,+++++++++,+++++++++ (OCDNCDUW-KwMHCD ><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>< DOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO O O O I I O O O O I O O O O O O O C O O C O O O O O O O O O O 100 FIGURE 0.6 GRAPH OF IMPULSE RESPONSE WEIGHTS [vk] xt = BCD32 Vendor Performance -.25 0. .25 .5 (k)+++++++++.+++++++++.+++++++++,+++++++++.+++++++++ VALUESEVk] 0 X 0. 1 X 0. 2 XX .1800808-01 3 X .137775E—01 0 X .1050058-01 5 X .8060088-02 5 x .5169078-02 7 X .0719988-02 8 X .361105E-02 9 X .276265E-02 10 X .2113588-02 11 X .161701E-02 12 X .1237108-02 13 X .906059E-03 10 X .7200878-03 15 X .5539678-03 16 X .0238158-03 17 X .3202028-03 18 X .2080638—03 19 X .1897828—03 20 X .1051908-03 21 X .1110818—03 22 X .8098338-00 23 X .5501698-00 20 X .0970158-00 25 x .3805508-00 25 X .2911028-00 27 X .2227008-00 28 X .1700088-00 29 X .l30372E-OH 30 X .9970168-05 31 X .763079E-05 32 X .5837978-05 33 X .0056378-05 30 x .3017028-05 35 X .2510218-05 36 x .200002E-05 37 x .153012E-05 38 x .1170538-05 39 x .8955968-05 00 X .5851818-06 01 X .5202018-06 02 x .0010038-05 03 x .3058208-06 00 X .2307308-06 “5 x .179585E-06 05 X .137392E-06 07 X .1051138-05 08 x .800170E-07 X 101 FIGURE 0.7 GRAPH OF IMPULSE RESPONSE WEIGHTS [vk] t —.5 -.25 0. = BCD92 % Change in PPI of Crude Materials 25 (k)+++++++++,+++++++++,+++++++++.+++++++++,+++++++++ (DGDQCDUW-C'wNI—‘O ><><><><><><><><><>< XXXXX XXXX XXXX XXX XXX XXX XXX ><><><><><><><><>< IOOOOOOOOOO 000...... 0 VALUES[vk] .106213E+00 .827565E-01 .6HH800E—01 .502397E-01 .391HHHE-01 .300995E-01 .237638E-01 .l85156E-01 .lHH265E-01 .112H05E-01 .875803E-02 .68238HE-02 .531682E-02 .HlH262E-02 .322773E-02 .251090E-02 .l959H9E-02 .15267HE-02 .118956E-02 .926853E-03 .722160E-03 .562673E-03 .H38HO9E-03 .3H1587E-03 .266109E-03 .207371E-03 .161573E-03 .125890E-03 .980879E-0H .76025HE-OH .59SH7lE—0H .H63963E-0H 361H98E-0H 281662E-OH 219058E-0H l70991E-0H 133228E-0H 103805E-OH 808802E-05 xt - BCD105 Real Money Supply - M1 —.25 0. .25 .5 (k)+++++++++.+++++++++.+++++++++.+++++++++.+++++++++ VALUES[vk] 0 X 0. l X 0. 2 X 0. 3 X 0. 0 X 0. 5 XXXXXXXXXXXXXX .326655E+00 6 XXXXXXXXX .212692E+00 7 XXXXXX .138088E+00 8 XXXXX .901725E-01 9 XXXX .587132E-01 10 XXX .382290E-01 11 XX .208920E-01 12 XX .162077E-01 13 X .105532E-01 1“ X .687138E—02 15 X .0070108—02 15 X .291318E-02 17 X .189683E-02 18 X .123507E—02 19 X .8001778-03 20 X .523616E-03 21 X .300937E-03 22 x .221991E-03 23 X .1005038—03 2” X .9011518-00 25 X .6128038-00 25 x .3990098-00 27 X .259803E-OH 28 x .169163E-00 29 X .1101058-00 30 X .717l8lE-05 31 X .066971E-05 32 X .3000558—05 33 X .197976E-05 3” X .l28907E-05 35 X .839337E-06 35 X .5065108-05 37 X .3558008-06 38 X .2316978-06 39 x .150863E-06 ”0 x .982301E—07 ”1 x .639596E-07 ”2 x .016055E-07 ”3 x .2711628-07 ”3 x .l76559E-07 ”5 X .110961E-07 ”5 X .708538E-08 “7 X .087389E-08 ”8 X .317309E-08 102 FIGURE 0.8 GRAPH OF IMPULSE RESPONSE WEIGHTS [vk] 103 cannot be made with the functions listed in Figures (0.1) through (0.8). We need to transform the impulse response weights in each function into beta coefficients in order to make this comparison. Comparison With Beta Coefficients To illuminate this requirement, consider an illustrae tion. The impulse response weights in these figures are analagous to regression coefficients, such as "6" in the following model. Suppose the true model is Y = a + bX + 8 Then suppose the line minimizing the sum of squared errors (the Ordinary Least Squares regression line) is Y = a + bX Then Y = a + bX + e A where e represents the residuals of the regression. The regressed line will pass through the point, (X,Y). i.e. Y = a + bX From this it follows that Y .. Y : b(X -- Y) + e or O Y,: Y = bO XA- X + e _ A0 _ or [Y-Y] : bl[XA'X]+X€3— C 100 In this last equation the input and the output are A O standardized. [b :3] is the beta coefficient, which measures 0 the relationship btheen the standardized input and the standardized output. Observe that it is obtained by multiplying the regression coefficient, 6, by the ratio of the standard deviation of the input to the standard deviation of the output. It can readily be compared with the beta coefficient Of any other similar regression in which the input and output are standardized. We can transform the impulse response weights in each of our functions listed in Figures 0.1 through 0.8 into beta coefficients, by simply multiplying each goefficient in each impulse response function by the ratio, Q 75, relevant to that particular model. This is done in O y Figures 0.9 through 0.16. In these eight figures the , magnitude of the relationship between each leading indicator and Industrial Production can be readily compared. Implications Upon examining these figures, we are immediately struck by a distinct fault which characterizes five of the relationships: the lack of any substantial lead. These series are hailed by the Commerce Department as leaders, which suggests that current movements in each indicator Should be consistently followed by movements in economic activity after some lag. They are developed with the expressed purpose of providing information about future 105 FIGURE H.9 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficients] Xt = BCDl Average Workweek The figures are obtained by multiplying the 09 weights in Figure 0.1 by ~0100”5 . .019806 The standard error of the series, (l—Blz)(l-B)log(x ), is .0100H6. t The standard error of the series, (1-812)(1-B)log(y ), is .019806. . t ' .25 . 0. .25 .5 (k)+++++++++,+++++++++.+++++++++,+++++++++,+++++++++ VALUES 0 XXXXXXXXXXXXXXXXXXXXXX .519380E+00 l XXXXXXXXXXXXXXX .351982E+00 2 XXXXXXXXXX .238536E+00 3 XXXXXXX .161655E+00 H XXXXX .109522E+00 5 XXX .7H2H30E-01 6 XXX .503101E-01 7 XX .300976E-01 8 XX .231077E-01 9 XX .156600E-01 10 X .106127E-01 11 X .712916E-02 12 X .087008E-02 13 X .330263E-02 10 X .223852E-02 15 X .151703E-02 16 X .102808E-02 17 X .696725E—03 18 X .072167E-03 19 X .319985E-03 20 X .216852E-03 21 X .106959E-03 22 X .995930E-00 23 X .670939E-00 20 X .057002E-OH 25 X .309979E-OH 26 X .210071E-0H 27 X .1H236HE-0H 28 X .960793E-05 29 X .653835E-05 30 X .003099E—05 31 X .300280E-05 32 X .203502E-05 33 X .137912E—05 106 FIGURE H.9 (cont'd.) -.25 0. .25 .5 (k) +++++++++ .+++++++++ ,+++++++++ , +++++++++ ,+++++++++ VALUES 30 X .9306238-06 35 X .5333908-06 36 X .0292008-06 37 X .290896E—06 38 X .1971398-05 39 X .1336008-06 00 X .9053958-07 01 X .613583E-07 02 X .015822E-07 03 X .281800E—07 00 x .190970E-07 05 x .1290228—07 05 X .877080E-08 07 X .5903988-08 08 x .002819E-08 107 FIGURE 0.10 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficients] x = BCD3 t Layoff Rate The figures are obtained by multiplying the 09 weights in Figure 0.2 by -20235 . .019806 The standard error of (1-812)(1—B)log(xt) is .20236, and the standard error of (l-B12)(l-B)1og(yt) is .019806 -.5 -.25 0. .25 (k)+++++++++,+++++++++,+++++++++.+++++++++,+++++++++ (DQOUW-L'WNHO XXXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXX XXXXXXXX XXXXX XXXXX XXXX XXXX XXX XXX XX XX XX XXXXXXXXXXXXXXXX><><><><><><><><><>< + VALUES .350311E+00 .321290E+00 .207630E+00 .190029E+00 .123063E+00 .112867E+00 .729392E-01 .668968E-01 .032312E-01 .396098E-01 .256232E-01 .235005E-01 .151869E-01 .139287E-01 .900129E—02 .825560E—02 .533508E-02 089310E-02 .316210E-02 .290010E-02 .187018E-02 .l71892E-02 .111083E-02 .101881E-02 .658391E-03 .603808E-03 .390230E-03 .357902E-03 .231290E-03 .212128E-03 137086E-03 125729E-03 812508E-00 705197E-00 08157HE-00 001679E—00 285030E-00 261780E—00 169170E-00 108 FIGURE 0.10 (cont'd.) -.5 0. (k)+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ VALUES 39 x -.155159E-00 00 X -.1002708-00 01 x -.919633E-05 ”2 x -.590302E-05 ”3 X -.505068E—05 00 x -.352200E—05 ”5 X -.323062E-05 ”6 x -.208775E-05 07 X -.191079E-05 08 X -.1237018-05 108 FIGURE 0.10 (cont'd.) -.5 0. (k)+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ VALUES 39 x —.155159E—00 00 x -.100270E-00 01 x -.919633E-05 02 X -.590302E-05 03 X -.505068E-05 00 X -.352200E-05 ”5 x -.323062E-05 06 X -.208775E—05 07 X -.191079E-05 08 X -.l23701E-05 109 FIGURE 0.11 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficients] xt = BCD8 Value of Manufacturers' New Orders These figures are obtained by multiplying the H9 weights in Figure 0.3 by . .019806 The standard error of (1-812)(1—B)log(xt) is .002878, and the standard error of (l-Blz)(l-B)log(yt) is .019806 —.25 0. .25 . QJ+++++++++,+++++++++.+++++++++,+++++++++,+++++++++ VALUES 6 XXXXXXXXXXXXXXXXXXXXX .5176258+00 l XXXXXXXX .1868568+00 2 XXXXXXXX .179660E+00 3 XXXX .608550E-01 0 XXX .623576E-01 5 XX .225102E-01 6 XX .216030E-01 7 X .7813008-02 6 X .751212E-02 9 X .271178E-02 10 X .260736E-02 11 X .9012208-03 12 X .900975E-03 13 X .326680E-03 1” X .3101058-03 15 X .1133888-03 16 X .10902lE-03 17 x .393552E-00 18 X .3783968-00 19 X .1365968-00 20 X .131330E-00 21 X .0701058—05 22 X .055809E-05 23 X .l60556E—05 2” X .1582198-05 25 X .5711098-06 26 X .5091568-06 27 x .1982388-06 23 X .190600E-06 29 X .6880558-07 30 X .6615608-07 31 X .2388158—07 32 X .229617E-07 33 X .8288908-08 3” X .7969708-08 35 x .287695E-08 36 X .2756168-08 37 X .998506E-09 38 39 00 01 02 03 00 05 06 07 08 -.25 FIGURE 0.11 (cont'd.) 0. (k)+++++++++.+++++++++.+++++++++.+++++++++.+++++++++ VALUES ><><><><><><><><><><>< 110 .25 .5 .960093E—09 .306580E—09 .333235E-09 .l20293E-09 .115660E-09 .017519E-10 .HOlHHlE-lO .100915E-10 .13933HE-10 .502977E-11 .083608E-11 111 FIGURE 0.12 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficients] Xt = BCD19 Index of Stock Prices These figures are ogtained by multiplying the 09 weights in Figure 0. 0 by _______ .019806 The standard error of (l- 81:)(1- B)log(xt ) is .006007, and the standard error of (1-812)(l— B)log(y:) is .019806 -.25 0. .25 .5 UO+++++++++.+++++++++.+++++++++.+++++++++.+++++++++ VALUES LDCDQCDU'l-C'WMF—‘O X X XXXXXXX XXXXXX XXXXX XXXX XXXX XXX XXX XX XX XX XX XX XX XXXXXXXXXXXXXXXXXXXXXXX OO 0 .156201E+00 .127386E+00 .103887E+00 .807228E—01 .690937E-01 .563080E—01 .05953HE-01 .307672E-01 .305629E-01 .209251E-01 .203269E-01 .165772E-01 .135192E-01 .110253E-01 .899lHHE-02 .733277E-02 .598010E-02 .087690E-02 .397727E-02 .320358E-02 .260523E-02 .215726E-02 .l75931E-02 .103077E-02 .117009E—02 .950203E-03 .778213E-03 .630650E-03 .517578E-03 .022100E-03 .30023HE-03 .280730E-03 .228906E—03 .186712E-03 .152269E-03 .l20179E-03 38 39 00 01 02 03 00 05 06 07 08 -.25 FIGURE 0.12 (cont'd.) 0. UO+++++++++.+++++++++.+++++++++.+++++++++.+++++++++ VALUES ><><><><><><><><><><>< 112 .25 .5 .101272E-03 .825901E—00 .673506E-00 .509295E-00 .007967E-00 .365330E—00 .297935E-00 .202975E—00 .l98153E—00 .161600E—00 .131789E-00 113 FIGURE 0.13 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficients] xt = BCD29 Index of Housing Starts These figures are obta§ned by multiplying the 09 weights in Figure 0. 5 by ________ .019806 12 The standard error of (1-B )(1—B)log(xt) is .11213, and the standard error of (1-812)(l—B)log(yt) is .019806 -025 0. .25 .5 UO+++++++++.+++++++++.+++++++++.+++++++++.+++++++++ VALUES (oooqmmszHo 000000000 0 0 0 0 0 0 0 0 XXXX .973315E-01 HFJPJHFAPHAPJH QOU'I-ITCDMl—‘O wwwwwwmmmmwwmmm :wwl—‘OLOCDQGU‘I-COONHO 0 0 0 0 com 0501 H (D XXXXXXXXXXXXXXXXXX><><><><><><><><><><><><><><><><><><><>< OOOOOOOOOOOOOOOOOOOOOOOOOOOO 0 0 0 0 0 0 . 0 0 0 0 0 0 0 0 . 0 . 0 0 0 0 (.0 \1 110 FIGURE 0.13 (cont'd.) -, 0. .25 .5 G<)+++++++++,?+§L+++++++,+++++++++ . +++++++++ , +++++++++ VALUES 38 X 0 39 X 0 00 X 0 01 X 0 02 X 0 03 X 0 00 X 0 05 X 0 06 X 0 07 X 0 08 X 0 115 FIGURE 0.10 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficientS] xt = BCD32 Vendor Performance These figures are obtained by multiplying the 09 weights in Figure 0.6 by ~17211 . .019806 The standard error of (l-Blz)(l-B)log(xt) is .17211, and the standard error of (l-B12)(l—B)log(yt) is .019806 0. .25 .5 UO+++++++++.+++++++++.+++++++++.+++++++++.+++++++++ VALUES LOCDNIOTUWSCDNHO X 0. X 0. XXXXXXX .156170E+00 XXXXXX .119082E+00 XXXXX .910101E-01 XXXX .699339E-01 XXX .535033E-01 XXX .009330E-01 XX .313160E-01 XX .239585E-01 XX .183296E-01 XX .100232E-01 X .107285E-01 X .820759E-02 X .627908E-02 X .080016E-02 X .367500E—02 X .281192E—02 X .215127E—02 X .l60580E-02 X .125916E-02 X .963325E-03 X .736999E-03 X .563805E-03 X .031312E-03 X .330023E—03 X .252086E-03 X .193166E—03 X .107783E-03 X .113062E-03 X .860987E-00 X .661763E-00 X .506285E-00 X .387336E-00 X .296333E-00 X .226712E-00 X .173007E-00 X .132696E-00 38 39 00 01 02 03 00 05 06 07 08 -.25 FIGURE 0.10 (cont'd) 0. . QJ+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ VALUES ><><><><><><><><><><>< 116 .25 5 .101520E-00 .776686E-05 .590208E—05 .050602E-05 .307796E—05 .266083E—05 .203568E-05 .155701E-05 .ll9050E-05 .911569E—06 .693398E-06 117 FIGURE 0.15 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta coefficients] xt = BCD92 % Change in PPI of Crude Materials These figures are obtained by multiplying the 09 weights in Figure 0.7 by -021531 . .019806 The standard error of (1-812)[xt] is .021631, and the standard error of (l-Bl2)(l-B)log(yt) is .019806 -.5 -.25 0. .25 Q)+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ VALUES 0 X 0 l X 0 2 X 0 3 X 0 0 X 0 5 X 0 6 X 0 7 X 0 8 X 0 9 X 0. 10 XXXXXX -.1157568+00 ll XXXXX -.901998E—01 12 XXXX -.7027958-01 13 XXX -.SH7580E-01 1” XXX -.026651E-01 15 XX -.332027E-01 .259012E-01 .201809E—01 HP4 \107 XX XX ll 18 XX -.1572018-01 19 X -.l22515E-01 20 X -.905575E-02 21 X -.703759E-02 22 X —.5795038-02 23 X -.051522E-02 20 X —.351800E—02 25 X -.270110E-02 26 X -.2l3573E-02 27 X -.l66006E-02 28 X -.129655E-02 29 X -.101022E—02 30 x —.787113E-03 31 x —.613281E-03 32 X -.H77801E-03 33 x -.372310E-03 30 X -.290087E-03 35 X -.2260228-03 36 x -.176105E-03 37 X -.l37213E-03 118 FIGURE 0.15 (cont'd) -05 -o25 0., 025 Qj+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ 38 39 00 01 02 03 00 05 06 07 08 ><><><><><><><><><><>< I VALUES .106910E-03 .832993E-00 .609029E—00 .505693E-00 .390012E-00 .306995E—00 .239197E—00 .186370E-00 .105211E-00 .113101E-00 .881508E-05 119 FIGURE 0.16 GRAPH OF IMPULSE RESPONSE WEIGHTS [Beta Coefficients] xt = BCD105 Real Money Supply - Ml These figures are obtained by multiplying the 09 weights in Figure 0.8 by 2 .019806 The standard error of (l- 81:)(1-B)1og(xt ) is .00702, and the standard error of (1-812)(1-B)log(y:) is .019806. -.25 0. .25 .5 QJ+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ VALUES 0 X 0. 1 X 0. 2 X 0. 3 X 0. 0 X 0- 5 XXXXXX .115506E+00 6 XXXX .752302E-01 7 XXX .089865E-01 8 XX .318961E-01 9 XX .207682E-01 10 XX .135226E-01 11 X .880089E-02 12 X .573305E-02 13 X .373292E-02 10 X .203057E202 15 X .158260E-02 16 X .103006E-02 17 X .670950E—03 18 X .H36873E-03 19 X .280056E—03 20 X .185215E—03 21 X .120597E-03 22 X .785235E-00 23 X .511283E—00 20 X .332907E-00 25 X .216763E-00 26 X .101138E-00 27 X .918935E—05 28 X .598370E-05 29 X .389612E-05 30 X .253680E-05 31 X .165179E-05 32 X .107551E-05 33 X .700288E-06 30 X .055975E-06 35 X .296893E-06 36 X .193310E-06 37 X .l25870E-06 120 FIGURE 0.16 (cont'd.) -.25 0. .25 .5 &Q+++++++++,+++++++++,+++++++++,+++++++++,+++++++++ VALUES 38 X .819567E-07 39 X .533638E-07 00 X .307063E-07 01 X .226200E-07 “2 X .lH7310E-07 ”3 X .959160E-08 00 x .620531E-08 ”5 X .006600E-08 06 X .260776E-08 ”7 X .l72001E-08 08 X .ll2250E-08 121 movements in economic activity. Furthermore, they are deemed useful in forming and implementing monetary and fiscal policy decisions aimed at stabilizing economic activity. To be truly useful in such a role, a leading indicator should Show a consistently long lead over Industrial Production. How long should this lead be? There are various decision rules about evaluating when a turning point occurs in any of these series. A common rule "accepted" at this time states that a series has experienced a turning point if a succession of increases (or decreases) is followed by three successive decreases (or increases). With this decision rule, a leading indicator must certainly show a consistent lead of more than three months over economic activity, if it is to be of any value in forecasting a turning point in economic activity. According to this rule, the recognition lag of a need for stabilization policy action will be three months (provided that the decision rule is followed). After this lag there will be an action lag and an outside lag before policy actions actually have a desired effect on economic activity. The action lag could be extremely long itself if fiscal policy is the desired tool, given the inertia of the Congressional decision-making process. The action lag could be relatively short if monetary policy is implemented. There has been much debate about the length of the outside lag in our economic system, though there is general 122 agreement that it extends at least over several months. In this light we see the need for leading indicators to display leads which are several months longer than the three months necessary to recognize a turning point. From Figures 0.9 througthlB we see that BCDl, BCD3, and BCD8 show no lead at all over Industrial Production. BCD19 and BCD32 display leads of just two months each. BCD105, the Real money supply, has a lead of five months, which may not be long enough to be very useful in the role desired, though it is much better than zero or two months. BCD29, the Index of Housing Starts, has a lead of nine months, which suggests that it may supply useful information as a leading indicator. Finally, the leading indicator with the longest lead of the eight considered is BCD92, the % change in the PPI of Crude Materials. Its impulse responSe function implies that a sustained 1% increase in (the seasonal difference of) the growth rate of the PPI will be followed by a decrease of about one tenth of 1% in (the seasonal difference of) the growth rate of Industrial Production after ten months, and further decreases in the following months. This negative relationship could reflect a movement along some demand curve, and thus follows our economic intuition. It is remarkable to note, however, that the Commerce Department uses this leading indicator in a positive role in the CLI [See the Handbook of Cyclical Indicators, pages 2, 3, 61.]. That is, BCD92 is used by the Commerce Department as if an increase 123 in the PPI were consistently followed by increases in Industrial Production. Our model in equation (0.15) and Figures 0.7 and 0.15 suggests that this is an inappropriate use of BCD92! It is important to note that this same negative pattern is implied by the estimated coefficients for the sample period ending in 1963 [See Table IV-2, (vii)]. This indicates that the negative relationship is quite stable, rather than just a phenomenon of the "supply shocks" in the early 1970's. Given all these considerations, we are left with just two of these eight leading indicators whicfilshould contribute positively to the CLI, as constructed by the Commerce Department: BCD29, the Index of Housing Starts, and BCD105, the Real money supply - M1. Conclusions The Commerce Department construction of the CLI is not backed by an appropriate theoretical framework, as outlined in Chapter II. Furthermore, our study indicates that five of the eight leading indicators considered display empirical relationships with Industrial Production which do not reflect the characteristics of a good leading indicator. They Show no significant lead time. This suggests that these five series may not merit the status given them by the Commerce Department. Their qualifications for the role of leading 12H indicator appear to be lacking. Three of the eight series considered display empirical relationships with Industrial Production which do reflect the characteristics of a good leading indicator: BCD29, BCD92, and BCD105. However, BCD92, the % change in the PPI of Crude Materials, proves to have a negative empirical relationship with Industrial Production, while the Commerce Department uses it in a positive role in the CLI. This leaves BCD29 and BCD105 which appear to be the only leading indicators of the eight considered, which might contribute positively to the Commerce Department's CLI. Given these observations, it is not surprising that the Commerce Department's leading indicator approach has been so unreliable. The question that remains is why so much effort has been, and continues to be, spent on its development and use in a predictive role. It seems clear that it will continue to be relied upon in its ex post role of verifying that turning points in economic activity have already taken place. Our study suggests that at best, it should be limited to this role. CHAPTER V MONEY AS A LEADING INDICATOR Introduction A huge literature exists on the role of Money in an economy, and its relationship to real GNP. Under the current state of thought toward Monetary Theory, what kind of relationship might we expect to see between Money and real GNP? Friedman describes the adjustment of nominal income to Monetary shocks in the context of a system of simultan- eous differential equations.1 This system is an attempt to explain (a) the short run adjustment of nominal income to a change in autonomous variables; (b) the short run division of a change in nominal income between prices and real output; and (c) the transition between this short run situation and long run equilibrium. In this framework it is suggested that anything which produces a discrepancy between the nominal quantity of Money demanded and the quantity supplied, or between their rates of change, will cause the rate of change in nominal income to depart from its anticipated (permanent) value. In general form, 125 126 * s d dY _ dY dM dM s d (a) aft- - f[(a{:‘) , —(—1_'E— , dt , M , M] where Y = Py = nominal income, P = the price level, y = real GNP, M8 = Money Supply, M(:1 = nominal amount of Money demanded, and a * denotes the anticipated (or "permanent") value of that variable. A linearized version of (a) might be: * s d dlogY _ dlogY dlogM dlogM ' —_—_— _ (‘3) dt ' ( dt ) + W dt dt ] + ¢(logMS - logMd) Next, the division of a change in nominal income between prices and output depends on two major factors: anticipations about the behavior of prices, and the current level of output compared with its full employment (permanent) level. We can express this in general form as: ,7, it dP _ dY dP dy , at ‘ gE'd—F’(EF)’(EF)’Y’YJ (b) dy dY dP * dy * at = “a? (at) 3 (a) ’Y’ V” where the form of g and h must be consistent with the identity, Y = Py. A linearized version (If (b) might be: 127 difigP : (difigP) + “Edifigy _ (dlwogY) ] + Y [logy - logy*] (b)' A dlogy : dlogy _ dlogY _ dldoth dt (—?fiT—) + (1 a)[ dt ( ) *1 Y [logy - logy*] In their general form, the equations in (b) do not by themselves specify the path of prices or output beginning with any initial position. In addition we need to know how anticipated values are formed. Presumably these are affected by the course of events so that, in response to a disturbance which produces a discrepancy between actual and anticipated values of the variables, there is a feedback effect that brings the actual and anticipated values together again. To put this in general terms, we must have: [Mm] = jtdldtogpmn , [91,12,61hn* = kEMWH , (c) y*(t) = m[y(T)], P*(t) = n[P(T)], where t stands for a particular point in time, and T for a vector of all dates prior to t. A disturbance of long run equilibrium introduces discrepancies in the two final terms in parentheses on the 128 right hand side of equation (a)'. This will cause the rate of change in nominal income to deviate from its permanent value, which through the equations in (b)‘, produces deviations in the rate of price change and output change from their permanent values. These will, through the equations in (c), produce changes in the anticipated values that will eventually eliminate the discrepancies between measured and permanent values. In the context of the above system, consider as such a disturbance of long run equilibrium, a permanent increase dlogMS dt frame in Figure 5.1 shows the time path of the money stock in , the growth rate of the Money Supply. The first before and after such a shock. The second frame shows the equilibrium path of nominal income. The slopes of the time paths in these two frames must be equal, since in equilibrium nominal income will grow at the same rate as the money stock, given the framework of Friedman's model. However, the equilibrium path of Y after this shock will be at a higher level than that of the Money Stock. This is because part of the increase in dtfiEY w111 consist of an increase in §%%§E. With this increase in inflation fully anticipated in equilibrium, it is now more costly to hold money. As a result there will be a decline in the real quantity of money demanded relative to income; i.e. a rise in desired velocity. This rise will be achieved by a rise in nominal income over and above that required to match the rise in the nominal quantity of money. 129 FIGURE 5.1 TIME PATHS OF NOMINAL INCOME AND ITS COMPONENTS, AFTER A MONETARY SHOCK log M log Y // t t t t o o d log Y dt 6? \ (Si—13%!) :1, _ _ _ (d log Y) dt t o d log y d log P dt dt (SQEELEH- _____ L _______ dt (Ci—19.8.1) ________ __ - _ (910813) ________________ dt 0 dt t t t t 130 The equilibrium path of nominal income will be like the solid line in the second frame of Figure 5.1 rather than the dashed line. We are interested in the adjustment process involved in the above scenario. It is apparent that in order to produce the shiftimmthe equilibrium path of nominal income from the dashed line to the solid line, nominal income must rise over some period at a faster rate than the final equilibrium rate. That is, there must be an overshooting, or a cyclical reaction in the rate of change in nominal income. The third frame in Figure 5.1 summarizes the various possible adjustment paths of difigY consistent with the theory presented above. The one common feature of all possibilities is that the area above the (difing line must exceed the area below. This chapter is concerned with the composition of the path of difigY describing the adjustment to a changeixx s (Ql285_) . We want to know how this time path is broken up dt into the time paths of 9%figx-and difigp, as expressed in the equations in (b)'. The time path of g%%§X-will reflect the usefulness of the nominal quantity of Money as an indicator of real GNP. One such possible set of time paths consistent with the equations in (b)' is diSplayed in the last two frames of Figure 5.1. Note that the vertical sum of these two time paths is the resulting path of difigY. Further note that in this picture, the time path of gAggy-initially rises, 131 following an increase in dififm, but eventually this rise is crowded out so that in the long run there is no rise in 9%figl. This reflects a situation in which money is neutral in the long run. The remainder of this chapter will examine the empirical relationship existing between Q%%§l and 9%figfl. Empirical Examination of the Relationship Between Money and Industrial ProductIon The Money Stock Data In this role, we are concerned with the ability of money to promote spending in the economy. Hence, an appropriate definition of money to consider is: MlB = Currency + Demand Deposits at commercial banks + Other Checkable Deposits at all depository institutions including NOW accounts, ATS, Credit Union draft shares, and Demand Deposits at Mutual Savings banks. It is worth noting that this is not the definition which Friedman would choose, since it excludes most Time Deposits. However, we feel it is appropriate for the work in this chapter. Data on M1 (= Currency + Demand Deposits) is available beginning with January, 1907. In 1960 and again in 1962 the Fed changed the definition of Demand Deposits at commercial banks. In 1960 the data were altered to include Demand Deposits due to mutual savings banks and 132 foreign banks, and to exclude float as well as CIPC.2 These numbers were published from 1907 to 1962, when the data were further amended to include foreign Demand Deposits with Federal Reserve Banks and Demand Deposits that banks in U.S. territories and possessions have at U.S. commercial banks.3 The data on this definition of M1 were then published beginning with 1907, and continued to be published until 1980, when the definition was changed once again. The data on this latest definition of M1 (namely MlB) have been published beginning with January, 1959. There is obviously a discrepancy between the old and new definitions, since they measure different things. Table V-l displays the components of the old Ml series as published in the 1960 definition, and the new MlB series as published in the 1980 definition. The last two columns show the discrepancy for the twelve monthly observations in 1959. We are interested in comparing phese two definitions since the definition of Demand Deposits in 1960 is closer to the definition of Demand Deposits in 1980, than is the 1962 definition. Note that the currency component is identical in the two definitions:h1Table V-l. The discrepancy arises in the Demand Deposit component (noting that Other Checkable Deposits are zero for the observations in 1959). The Demand Deposit component in the 1960 definition exceeds the Demand Deposit component in the 1980 definition by the amount of Demand Deposits due to foreign official institu- tions. 133 boo.H o.H N.::H 5.:HH m.mm «.mzH >.mHH m.mm mH.mm moo.H m.o :.N:H N.mHH «.mm m.m:H H.:HH «.mm HH.mm moo.H m.o m.H:H m.mHH o.mm N.N:H «.mHH o.mm OH.mm moo.H N.H m.o:H m.HHH H.mm H.N:H o.mHH H.mm m.mm moo.H N.H m.o:H :.HHH H.mm >.H:H m.NHH H.mm m.mm OHo.H :.H v.0:H m.HHH H.mm H.~:H o.mHH H.mN h.mm HHo.H m.H m.mmH G.HHH m.mm :.H:H m.mHH m.mm m.mm HHo.H m.H N.mmH m.OHH b.mm >.o:H o.mHH n.mm m.mm HHo.H m.H m.o:H m.HHH m.mm m.H:H m.mHH m.mm :.mm mHo.H m.H o.mmH m.oHH m.mm m.o:H m.mHH m.mm m.mm HHo.H m.H m.mmH m.HHH :.mm :.H:H o.mHH :.mm «.mm HHo.H m.H m.N:H m.:HH m.m~ :.::H w.mHH m.mm H.mm H H H H Am 2\ 2V Am ZILAVAmCOHHHHQV amCOHHHHQV OHpmm .MMHQ mHz HMHOH .Q.o.o + .Q.m zocm9950 Hz HMHOH AHAH hunchnso .oz\.aw. AommvaGOHHHCHmOQ Bozu AommvaCOHpHCmeQ OHOU mmmH a>nmscmh..CH.mHanHm>m .mmwsmm ommH n mHz nzmH X>SMSCMb EH mHanHm>m .wmwhmm ommH u H: mmmH I mMHmmm MUOHm Mmzoz HI> MdmM60KJMFQKJNFHPJHFHFJHFHPJHFH UhruJNFJCDOCD\Jm(flI?wWOFJOLDGDQCDULCQJNFJCDQCD\JOCDifwrokJO XXXX XXXXXX XXXXXXXX XXXXXXXXXXX XXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXX XXXXXXXXX XXXXXXX XXXXXX XXXXX XXX X XXXX XXX XXXX XXX XXXX XXXX XXXXXX XXXXXX XXXXXX XXXX XX X X X XX XX XXX XXXX VALUES [Vk] .56397 1.01303 1.32183 1.90079 2.09938 2.55300 2.90339 2.98310 3.30018 .52007 .60022 .61277 .70121 .51788 .05020 .12625 .80079 2.50138 2.36500 2.09065 2.16603 1.85196 1.60538 1.26265 .93682 .71901 .33259 -.06020 -.53510 -.38670 -.66120 -.36123 -.50037 -.63566 —.96803 -1.01581 -1.02119 —.65595 -.20937 -.05891 -.06906 -.05671 .15900 -.10106 -.01090 -.56157 wwwwwwww 100 FIGURE 5.3 (cont'd.) (—2.0) 0. (2.0) (k).+++++++++.+++++++++.+++++++++.+++++++++. VALUES [Vk] 06 XXX -.09006 07 XXX -.37230 08 XX -.25003 105 cannot be represented parsimoniously as a ratio of two polynomials in B. Furthermore, we must operate within an upperbound of eight or nine total parameters in our model, due to the limitations of our time series computer program. We have overcome these difficulties by filtering the data on Mt prior to estimation, in a 20-month moving average which follows one half of the period of the cosine function. This is done as follows. 1 period = 08 months = 2Tr radians - 1L ‘ 1 month - 2” radians . 23 in i 12 Filtered M = FM = Z cos(——)B (l-B )(l-B)log(M ) t t 1:0 20 t We then use FMt as our input series in the following transfer function. (5.5) (l-Bl2)(l-B)log(y£) = The 20th order polynomial in the O .________ + 1-6 B,” [FMt] N 0.) 1t 20 denominator will work with our 20-month moving average of Mt to make an impulse response function, vl(B), which resembles the damped cosine wave we desire. If -1 < 6 20 function will appear as follows. FIGURE 5.0 (520 /——\ = -.5) < 0, then this impulse response lag in months 106 This picture is still not ideal, as it implies an impulse response function which is discontinuous at all lags which are multiples of 20. We can eliminate these discontinuities by altering our filter slightly: 23 . . (5.6) Filtered M = FM = [ X [A]cos(££)Bl](l—B12)(l-B)log(Mf) t t 1:0 20 1.0 for i=0, 1, ... ,12 where A = ‘520 for 1:13, ... ,23 Note that this filter will change the appearance of Figure 5.0 as follows. r\\\\\\ ,,/"'_—-‘“‘~\\ lag in 12 20 36 08 60 72 FIGURE 5.5 (520 C -.5) . We can arrive at a model of this form by first choosing a value of 62”, and filtering Mt according to (5.6) with this value. Then we can estimate the transfer function, (5.5), and check the value of 62”, to see if it differs substantially from our initial choice used to filter Mt' 'If it does, we can use the new value of 62” to filter Mt again with (5.6), and then re-estimate (5.5). We can continue this iterative procedure until the estimate of 6 does not vary appreciably from the value used to filter 20 M Using this procedure will give us a transfer function t0 between Mt and y1: with a "smooth" impulse response function, as in Figure 5.5. 107 In the following work we iterate on 52” until the estimate remains within a band of (:.005) from the value used to filter Mt' Since the estimate of mo is in all cases less than (.2), this will result in a discontinuity at lag 20 in Figure 5.5 of less than (.001)[=(.2)*(.005)]. We are now ready to estimate this model. But we must first consider some problems with our sample period: January, 1907 - December, 1979. Does the transfer function, (5.5), adequately describe a stable relationship throughout this entire period? We suspect that the oil crunch of 1973 represents an episode for which (5.5) is inadequate. There is a substantial literature on this topic, concerning the supply shock to the economy resulting from the increase in energy prices.5 This literature dwells on the change in the structure of the world economy after this shock, and the presumed impact on real and potential output. Tatom states that "the large increase in the cost of energy resources from 1972 to 1977 has had profound effects on productivity, investment, and the long term growth path of the U.S. economy." The study of Rasche and Tatom produced empirical results which "support the argument that the new energy regime imposed in 1970 permanently reduced potential output, and suggests that "failure to account for energy prior to 1973 is not critical, but that serious inconsistencies arise when the sample period is extended to include recent years." It is apparent that the supply shock of 1973 changed I 108 the world we are studying. This phenomenon enters our model as outlined in the beginning of the chapter in equation (b), as a sudden change in anticipated potential output, y*. For example in equation (b)', (log y*) will have changed drastically during this episode. This will result in alterations in the time paths of prices and real output. These considerations move us to believe that the presumed stable relationship between Mt and §t should pp: be expected to hold during this oil crunch of 1973, and should pp: be expected to account for the change in the world since then. The transfer function in equation (5.5) would likely overpredict yt during the oil crunch, and subsequently prove to be inadequate. We can examine this possibility by first estimating the single-input transfer function in (5.5) over the sample period May, 1950 - September, 1973, the period prior to the oil crunch. The following model is the result.6 BCDH7 Index of Industrial Production yt = xt = FMt = Filtered Mt as in equation (5.6) with 6 = -.5207 20 (5 7) (1-812)(l-B)lo ( ) - ~———m£——— [x 1 + 1-612312 a ’ g yt ' 1 5 B20 t 1-618 t 7 20 6 = .1877 3 = -.5251 6 = .8005 0 = .2776 0 (.059) 2” (.252) 12 (.039) l (.052) 2 _ _ Xus - 37.7 RSE — .0135 —2 109 We are interested in how this model will forecast over the next 18 months outside the sample, during the oil crunch. Table V-3 shows the 18 one-step—ahead forecasts obtained from this model by including an additional observation on FMt and yt at each step. The forecast errors show that the model drastically overpredicts yt in late 1970, though it performs fairly well for most of the other 18 months considered. Thus our suspicions as to the adequacy of this single-input transfer function during the oil crunch are possibly well-founded. Expanding the Model to Account for the Energy Price Supply Shocks of the Early 1970's - BCD92 We can correct this situation by considering a second input which might capture the effect of the oil crunch in 1973, and thus enhance our model's ability to predict yt during this period. One such possible input is BCD92: the percent change in the PPI of Crude Materials. Recall that this series represents one of the three Commerce Department leading indicators examined in Chapter IV, which displays the characteristics a good leading indicator is expected to have. The second to last column of Table V—3 shows the monthly observations of BCD92. This series displays a noticeable increase in late 1973 and early 1970. Recall from Chapter IV that this leading indicator has a lead of approximately ten months over Industrial Production. This suggests that 150 HmHmsvo< mo some 0 mg .mmmeQEoo Mmzm opp £OH£3 OHQMHQO> vampcmamo may mo . mmmm.omH - S some may mo :oHpsoooso - oHo mommoo.m - mmzm ommmmo.m_u mmzm u possm osmoom :60: Hoom mm: :mmmwm.: H mm: Honhm mpmsvm cmwz mo mo.Houuommoom.m nos." soHpsooose mosmHsm>oo mmmmom H mo cosmsHpmo Hooos was ssz u 0x moHs .o.H 02Hom mqmal2t + Elt On multiplying through this by allt-k’ we obtain (5°20) “11t-k81t = v1(B)°‘11t-k°‘11t + v2(B)°‘11t-k°‘12t + allt-kglt If we make the assumption thatallt_k is uncorrelated with alt for all k, taking expectations in equation (5.20) yields the following. 156 l (5.21) E[a 8 ] = vl(B)E[allt_kallt]'+v2(B)E[o llt-k lt llt-Kal2t (k) = v (B)Y (k) + v2(B)Y (k) or Y 0‘11 B1 1 0110111 C111‘112 Since allt is white noise, the first term on the right hand side of equation (5.21) reduces to [Vkoa 2]. Finally, if 11 (k) is zero for all k, then equation (5.21) reduces Y%1%2 to the following. (5 22) (k) - o 2 - (1118 (k) . Ya B - Vk all 01" Vk - O 2 a 11 where Ya B (k) = E[0 llt- k Blt] is the cross- covariance at 0‘11 1 lag k between allt and Blt Therefore, pull 81(k)081 YO‘ll 81(k) (5.23) v = since 0 (k) = k Ga 0"1181 ° 08 11 . “11 1 Hence the cross-correlation function between the prewhitened first input and the correspondingly transformed output is directly proportional to the impulse response function, vl(B). We can thus identify the form of the first impulse response function by estimating the cross-correlation function, r (k), and the standard errors of the pre- 0‘1161 .whitened first input and the similarly transformed output, and then substituting into equation (5.23). (5.20) v = k 5a ll 157 It is important to emphasize that this procedure rests on the assumption that Ya a (k) is zero for all k. 11 12 We can estimate this cross-correlation function between the prewhitened first input and the correspondingly transformed second input, in order to evaluate the applicability of this assumption. If the coefficients of r (k) are not significantly different from zero, then we canigt reject the hypothesis that the assumption holds. Note that to identify v2(B), we will use the cross- correlation function between the prewhitened second input and the similarly transformed output, Ya B (k). The use 22 2 of this procedure will rest on the assumption that Ya a (k) is zero for all k. The applicability of this assumpticzm21 is testable in the same way we test the assumption regarding the identification of vl(B). In summary, this analysis shows us that if r (k) :912 and r (k) display coefficients which are not signifi- “22“21 cantly different from zero, then the cross-correlation function between each prewhitened input and the correspond- ingly transformed output can be used separately to identify the respective impulse response functions. In continuing our empirical analysis, we now wish to build the two-input transfer function, with FMt and BCD92 as our two inputs. In order to be able to identify the two impulse response functions separately, we are interested in the two cross—correlation functions, ra a (k) 11 12 158 and rd 0 (k). These are presented in Table V-u. 2Thilstandard error of any given cross-correlation coefficient, rab(k), is approximated by 1//fi:k.8 With n = 352 in the sample of the transfer function we are building, the standard error of ralla12(0) = the standard error of ra22a21CO) = l//352 = .0533. To test the hypothesis that the estimated coefficients are not significantly different from zero, each coefficient (at lag zero) should be compared with (1.96)*(.0533) = .10u5. In the estimated cross-correlation function, ra a (k), all the coefficients are less than .1095 except 11 12 the coefficient at lag 16; r (16) = -.111. “11a12 The standard error of this coefficient = l n-k : ————l = .05146. {352-16 and (1.96)*(.0596) = 1.07. Therefore, r (16) is "significantly different from “11312 zero" at the 95% confidence level. However, if we consider the whole set of #9 coefficients in the cross-correlation function, we would expect about 2 1/2 coefficients to be "significantly different from zero" at the 95% confidence level. Hence the cross-correlation function, ra a (k), 11 12 supports our assumption which implies that we can use the cross-correlation function between prewhitened x1t (= Filtered Money Supply) and the similarly transformed yt (= Industrial Production Index), to identify v1(B). 159 TABLE V-u Cross Correlations Series all - Prewhitened Filtered Money Supply (62” = -.5600) Series a12 - Prewhitened BCD92 Percent Change in PPI of Crude Materials n = 352 Mean of Series all = .u2260B-03 St. Dev. of Series all = .uuzosB-oz Mean of Series a12 = .93668E-04 St. Dev. of Series a12 = .2182uE-01 Number of Lags Cross Number of Lags Cross on Series a Correlation on Series a Correlation 11 12 (k) ra a (k) (k) ra a (k) 11 l2 12 11 0 -.023 0 -.023 l .018 l .023 2 -.0u2 2 .008 3 —.026 3 -.025 Q .090 H .008 5 .010 5 -.00N 6 -.06H 6 .0u2 7 -.005 7 -.055 8 -.027 8 -.06H 9 .077 9 ..060 10 -.063- 10 —.0Hl 11 —.oon 11 .059 12 -.051 12 .019 13 .057 13 -.005 1a .080 1” -.068 15 -.020 15 -.016 16 -.111 16 -.021 17 .062 17 .020 18 .030 18 -.0u7 19 -.022 19 .126 20 -.019 20 -.098 21 .021 21 —.060 22 .003 22 .032 23 .OHS 23 -.038 2H -.079 2” -.032 25 -.005 25 .060 26 .005 26 .068 27 -.037 27 —.030 28 -.002 28 —.051 29 -.035 29 .021 30 -.003 30 -.016 31 .030 31 -.056 32 .015 32 .095 33 -.035 33 .015 160 TABLE V-H (cont'd.) Number of Lags Cross Number of Lags Cross on Series all Correlations on Series al2 Correlations (k) ra a (k) (k) ra a (k) 11 12 12 11 3H .006 3H —.0H8 35 -.012 35 -.027 36 .077 36 .052 37 -.039 37 -.018 38 -.0H6 38 -.031 39 -.032 39 .030 H0 .070 H0 .093 Hl .00H H1 -.105 H2 -.025 H2 .073 H3 -.033 H3 ‘ —.029 HH .025 HH -.020 H5 .012 H5 -.007 H6 -.010 H6 .0H8 H7 -.037 H7 .031 H8 —.016 H8 -.055 Prewhitening: (l-.8673B)(l-.2197B-.3052B3)(l+.6109812)[FMt] = 10 13 (l+.1173B-.13H3B -.1819B )at " same model on (l-B12)[BCD92]. 161 TABLE V-H (cont'd.) Cross Correlations: Series a22 - Prewhitened BCD92 Percent Change in PPI of Crude Materials Series a21 - Prewhitened Filtered Money Supply (62u=-.5600) n = 352 Mean of Series a22 = .80105E—03 St. Dev. of Series a22 = .lH037E-01. Mean of Series a21 = .393HOB-02 St. Dev. of Series a21 = .9307HE-02 Number of Lags Cross Number of Lags Cross , on Series a22 Correlation on Series a2l Correlation (k) r (k) (k) r a (k) “22“21 0‘21 22 0 -.015 0 —.015 1 .0H9 1 .029 2 .061 2 .02H 3 .026 3 .081 H .021 H .0H6 5 -.002 5 .06H 6 .00H 6 .061 7 -.0H3 7 .037 8 -.055 8 .025 9 .001 9 .018 10 —.069 10 .008 11 -.050 11 .006 12 -.107 12 .006 13 -.l22 13 .053 lH -.139 1H .030 15 ~.13l 15 .058 16 -.117 16 -.021 17 -.078 17 .012 18 -.031 18 .011 19 -.015 19 -.002 20 -.036 20 -.015 21 -.003 21 -.023 22 -.029 22 -.007 23 -.029 23 -.015 2H -.011 2H -.05H 25 .0H1 25 -.00H 26 .080 26 -.019 27 .029 27 .0H3 28 -.005 28 -.002 29 .007 29 .017 30 .029 30 .03H 31 .002 31 .021 32 .033 32 .008 162 TABLE V—H (cont'd.) Number of Lags Cross Number of Lags Cross on Series a22 Correlation on Series a21 Correlation (k) Pa a (k) (k) ra a (k) 22 21 21 22 33 .083 33 -.002 3H .02H 3H .0H2 35 -.006 35 .009 36 .019 36 .027 37 -.002 37 -.005 38 .030 38 -.038 39 .03H 39 .010 H0 .053 H0 -.029 H1 .016 H1 -.035 H2 ' .069 H2 -.009 H3 .027 H3 -.027 HH .011 HH -.0H2 H5 .056 H5 —.0H5 H6 .0H8 H6 -.025 H7 .00H H7 -.0H5 H8 .011 H8 -.03H Prewhitening: (1-.38508-.265883)(1-B12)[BCD92] = (1-.15H2B2-.8120B12 + .197581u) at " same model on the levels of FMt' 163 The estimated cross-correlation function, ra a (k) displays five coefficients which are "significantly2different from zero." Furthermore the tendency of positive coefficients to be followed by positive coefficients and of negative coefficients to be followed by negative coefficients, seems to indicate that there is some correlation inherent in the relationship between these two series which is not effectively eliminated by the prewhitening model for BCD92. This is somewhat disturbing. However we are reassured by the fact that H3 of the H8 coefficients are not significantly different from zero. This is the key characteristic in our analysis of the applicability of the assumption that all coefficients in Ya22a21(k) are zero. Hence we anticipate that the cross-correlation function between the prewhitened input, x (= BCD92), and the correspondingly transformed 2t output, yt(=Industrial Production Index), will be instrumental in identifying v2(B). Estimating_the Two Input Transfer Function We have already identified and estimated separately, the two transfer functions with each of these inputs as the single input. Thus we know what to expect as the form of the two impulse response functions, vl(B) and v2(B), in our two-input transfer function. With this in mind, we build the following model.9 yt = BCDH7 Index of Industrial Production 16H x FMt = Filtered Mt as 1n (5.6), w1th 62H::-°5231 1t BCD92 % change in PPI of Crude Materials X2t Sample: May, 1950 - September, 1973 (n = 281) .0) (5.25) (1—B12)(l-B)log(yt) = ———°—2¢ [xlt] 1-5 8 2n (.0, o 10 12 + l—6iB B (l-B )[x2t] 1-812812 + 1-¢1B at w = .1835 52a = -.5208 w' = -.061H 51 = .7805 (.058) (.260) O (.0u5) (.176) 912 = .7926 ¢1 = .25u0 (.ouo> (.051) ‘2 _ _ —2 _ XHB _ uo.u RSE - .013u R - .SHHl A comparison of the coefficients in this equation with those of equation (5.7) on page 1H8 shows that the addition of the second input, BCD92, does not change the appearance of the first transfer function much. In particular, the coefficients 00, 62”, 812, and $1 are quite insensitive to the addition of this second input. It is also interesting to compare the coefficients 8; and 6i in equation (5.25) with the coefficients 00 and 61 of the single-input transfer function with BCD92 as the input, which appears in Table IV-2 in Chapter IV. These coefficients are also quite insensitive to the addition of the second variable, FMt' 165 We are now interested in how this model will forecast over the next 18 periods. Table V-5 shows the 18 resulting one—step-ahead forecasts. We see improvement in reducing the large forecast errors in late 197H that appear in Table V-3. Furthermore, the Theil Decomposition statistics show marked improvement. In particular, the RMSE is reduced to 1.758H6 from 2.053285. These character- istics suggest that our second input, BCD92, is useful in the role desired. Our third step in building this model is to re- estimate the two-input transfer function in equation (5.25) over the sample period May, 1950 - March, 1975, the period through the oil crunch. The resulting model follows.lo yt = BCDH7 Index of Industrial Production : : ° ° ° 0 : .. x1t FMt Filtered Mt as 1n (5.6),w1th 2H .5520 x2t = BCD92 % change in PPI of Crude Materials Sample: May, 1950 - March, 1975 (n = 299) m (5.26) (l-B12)(l-B)1og(y ) = ————9——— [x J t 1- B29 1t 529 w. 0 10 12 + W B (l-B )[X2t] 1‘812312 + ———————— a 1—¢1B t w = .1772 5 = -.5568 3' = -.0993 3' = .7707 O (.060) 2” (.290) O (.093) 1 (.123) 6 = .7699 3 = .2827 12 (.092) 1 (.061) 2 = 39.6 RSE = .0139 82 = .5991 x96 166 mm: mo wm.: u mmmmma. u m: > mm: mo wm.m n momomo. u 2: :Ho. 0 mmmm.wma l om:mmn.H u mmzm mammn.a u mmzm Hmammo.m 9 mm: smawmm.a u m 5mm :m.| m:m.| m.HHH m.mHH m.moa m:s.maa NH.:> mam mo.:c :mw.:n m.:HH >.NNH :.mHH :mm.maa HH.:5 mmm mm.mu wms.mu m.mma w.NmH m.mmH mmm.mNH oa.:> 2mm Hm.Hn om>.Hn H.mma m.mmH m.HmH omm.:mH m.:> mmm mm. 035. m.mmH :.mma m.HmH oms.:ma m.:h «mm mo.n 30H.) :.HmH o.mmH H.mma :om.HmH 5.:h Hmm H3. mam. m.>NH m.oma m.mma Hms.mma m.:h omm mm. mm:. m.mmH :.wma m.HmH nom.:ma m.:b mmm ms.H mmm.m >.HmH m.mma o.mmH msm.mma :.:s mmm :m.) mm:.u m.mmH m.mma m.mNH mmm.oma m.:s 5mm mm. was. m.oma m.mmH h.mma who.oma «.25 mmm mm. :ms. m.mma m.mma s.mma moo.mma H.3b mmm om.| Hmm.u m.mma m.mma m.mma Hmm.mma ma.ms 1mm mo.m( www.ml s.mmH s.mma m.mma www.mma Ha.ms mmm :N. 3mm. m.mma H.oma H.oma www.mma oa.ms «mm m:. omm. m.mma m.mmH «.Hma omm.:ma m.mw Hmm Hmspo< 90990 pmmom9om AH.+.O.HV 9mmmD 9m304 pmmom9om .oz\.9w .o.H mo w Apmwom9omuamzpoo ompmaflpmm HmooE £993 Nmaom u Nx 6cm AHMNm.- u o 929 u 9x £992 .6.9 mcflpmmompoa ml> m4mmH mm:.H:H m.bu mmm 30.: mmo.| m.>mH m.o:H m.mma www.mma 1.5n :mm mm.) :ms.n N.mma 3.0:H m.mmH :mm.mma m.bn mum 3m. :3H.H m.mmH o.mmH ~.HmH mmm.:ma «.mn mwm mm. mm:. m.mmH m.mma m.mma NmH.mmH H.55 Hmm Hm.n was.) m.mma m.mma m.mNH www.mma ma.m> omm 3H. mma. m.mmH :.HmH m.:~a hHH.me Ha.mh mam ms. :mo.H H.mma 3.:ma m.bma moo.HmH oa.wn mam ma.) >HN.I m.mmH 3.5mH b.omH nao.:ma m.mh mam OH.NI mam.m| m.:mH m.oza s.mma mHH.bmH w.oh mam Hm.| Hoo.al s.HmH N.mmH :.mNH Hmp.mma u.mh mam mm. 5mm. m.mmH :.mma H.mNH mom.mmH m.m> :Hm om.H| wmm.H) N.mma m.mma :.Hma mmn.:ma m.wb mam Hm.) mos.) o.omH >.mma ~.wma mo:.oma :.mn «Hm ms.) snm.n s.mmH o.mmH :.mmH www.mma m.mn HHm pH.HI mom.al m.mmH :.mma m.mma moH.omH N.wn oam mo.H mHm.H m.mma m.oma m.mma «mm.mma H.mh mom mo.H m:m.H m.mmH 0.:NH m.nHH mmm.oma mH.mn mom :H.) :ma.n m.mHH o.mmH o.nHH :mm.mHH Ha.mh pom om. 03s. m.mmH m.mmH o.oma omo.mmH oa.mb mom Ho.Hn Nmm.Hn :.mmH m.mmH m.mma mow.wua m.mb mom us.) msm.| m.mmH H.omH u.mNH mnm.mNH m.mn :om mm.a Hum.a :.HNH m.mmH >.mHH www.maa b.mm mom mm.H m:m.H m.:HH m.mHH H.oHH www.maa o.mn mom NH.N Hmm.m «.mHH n.mHH m.mHH www.maa m.mn Hom mm. omm. m.mfifi H.mHH :.0HH on.mHH :.mn oom :o.m som.m o.mHH m.mHH m.boa mmm.oHH m.mn mmm Hmsyo< 90990 #mmom9om HM590< 90mm: 9w304 pmmom9om .oz\.9w .o.H mo w Apmmom9om1HMSpo mqm mqm mqm<8 169 mm: 90 0H.00 n 00HHH0.H n 0: 0 00: 90 00.0 n 0H0000. u 0: 0:H000.H u 002 0H0. u 000:0.00H I 002 90 00.0 n :0H000. u 23 000000.H u m M4m¢H 170 w = .1726 52” = -.5583 wé = -.1036 0i 3 .68H2 (.052) (.196) (.0H2) (.1H8) 8 = .7776 0 = .2777 12 (.037) 1 (.056) 2 _ _ —2 _ XH6 - HH.1 RSE - .0129 R - .5775 Again, note that the coefficient estimates are extremely stable as we increase the sample size from n = 299 to n = 352, from equation (5.26) to (5.27). Implications of the Final Model This is our model for the entire sample period, describing the relationships between Mt and yt and between BCD92 and yt. We are especially interested in the impulse and step response functions between Mt and yt, in order to examine in more detail the empirical evidence regarding the monetarist proposition outlined at the beginning of this chapter. This impulse response function is developed below. Let mt = (1-B12)(l-B)log(Mt) Then the impulse response function is: 01(B) 00 (5.28) vl(B)[mt] : W [mt] 3 W [FMt] ‘ 29 where FMt is defined as in equation (5.6), as follows: 23 i“ i 1.0 for i = 0, ... ,12 FMt = [ Z (A)cos(§E)B )mt; with A = i=0 -6 for i = 13, ...,23 2H 171 PMt = [1.0 + .99B + .96682 + .92983 + .8668” + .79385 + .70796 + .60987 + .588 + .38389 + .259810 + .13311 - (—62u) .13813 - (-62u).259Blu — (—62u) .383815 - ('529) .5816 - (-52u).609817 - ("529) .707818 - (”529’ .793819 — (~52u).866B20 - (’529’ .92H821 - (-62u) .966822 - {-62u).99B23] mt Thus 01(8), the polynomial in B comprising the numerator of vl(B), is simply mo multiplying the above twenty-third order polynomial in B. A 23 in i (5.29) 01(8) = 00 .Z (A)cos (§H)B 1-0 When combined with 61(8), the denominator of vl(B), the resulting impulse response function is of the following form. (5.30) vlCB) ”o 2 (A)cos(L P)B -+(62u) Z0 (A)cos(L BEB‘fi i=0 i= + N70 O[: X (A)cos(L M1][8::J A A 23 o o 3 in 1 72 (02”) Swo[i:0(A)COS(:fi)B ][B J + + A From equation (5.27) we have 00 = .1726, -62H = .5600, and 62” = -.5583. Using these estimates in equation (5.30) yields the infinite order polynomial in B comprising vl(B). The first H8 coefficients of this impulse response function are listed and plotted in Figure 5.6, as well as those of the associated step response function. 172 IVA:N IVA:N :vmzm x000. x000. me. O< x000.0 3 O< x000.v 3 O< A000.V 3 O< 0:00.V 3 H0>0 0000<> 0000.: 0000.: 0000.: 00:0.: 0000.: 0000.: 0NHO.: .0 :mmo. 0::0. H000. 0000. HO0H. ommH. 000H. 00:H. 000H. 000H. 000H. 0NOH. .H 0. xxx xx xx xx xx xx x x x xx xx xxx xxx xxx xxxx xxxx xxxx xxxx xxxx xxxx .0 H9009>0 0900903 00200000 0000029 no mm<00 0.0 MODme .+++++++++.+++++++++.+++++++++.+++++++++.H 0.: 0H 0H 0H 0H 0H :H 0H NH HH 0H 0 0 0 0 0 : 0 m H 0 0 0 173 .IVA A333.:3A3N3-VA3 :00: VAIvaO 3 vaom ASN.3A3N3¢A3Nm36,,3.v .-3A3N3-3AH NWoom A3.3.3AH vaom A33.3A3 NWoom A33N.3A3 NWoom A333.3A3N 33 63 A3.3A3N mvom A333.3A3 chom A9ON.3A3 Nmoom AmmN.VA3 N33 63 A333.VA3 Nmoom Azmm.VA: NWV 03 A333.3A3N Woom A30.VA3N moom A3.33A3vaom A33. -3A3N3.360 A333.-3A3 N3 360 A3Nm.:VA3N3-V£ A333.:3A3N 3 Com H 0000. xx 0: 0000. x 00 0:H0. x 00 0000. x 00 .o x 30 00H0.: x 00 0000.: xx :0 0000.: xx 00 00:0.: xx 00 0000.: xx H0 H000.: xx 00 :000.: xxx 00 :000.: xxx 00 0000.: xxx 00 H000.: xxx 00 :000.: xxx 00 :000.: xxx :0 0000.: xxx 00 :000.: xxx 00 0000.: xxx H0 0000.: xxx 00 0024<> w+++++++++.+++++++++m+++++++++.+++++++++.H00 . 0. . 0.: 0.0.99000 0.0 m0Dme 17H A3.33A3N0 3A3 A33.-3A3N3-VA3 A330.-VA3N3-VA3 A3N3.-3A3N3-3A3 . :0 A333 -VA 3-3A3 . :0 A339 -VA 3-3A3 A939.-3A3N3-3A3 .: :0 A333 3A 3-3A3 N3363 9 3333. Nmoom n 3333. Nmoom u HNmo. vaom n 3333. vaom n 0333. vaom u 3N3o. NWvom u N333. Nmoom n mNmo. H 330 0003<> xx xx xx xx xx xx xx xx 0: 0: 0: 0: :: 0: 0: H: .+++++++++.+++++++++.+++++++++.+++++++++.x00 OH m. .0 A.U.9coov 0.0 m0DwH0 0.: 175 0omH. mmm0. oo:m. om0:. H00m. thm. mmab. mmow. omom. m0mm. ombo.H .m0mH.H mo00.H mmh0.H Hm0m.H Hmmm.a Homm.a 000:.H 000:.H momm.a mmmm.H mmm0.H 0mmH.H Hmno.H Ammo. 0mam. name. 00am. mm:m. m0hH. 3x>3 mmpq<> xxxxx xxxxxx xxxxxxxx xxxxxxxxxx xxxxxxxxxxx xxxxxxxxxxxxx xxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxxxxxxx xxxxxxx xxxx .+++++++++.+++++++++.+++++++++.+++++++++.+++++++++.A m.H o.H m. .o mxmva>u mhmem3 mmzommmm awhm mo mmu mmaq<> xxxxxxxx xxxxxxx xxxxxx xxxxx xxxx xxx xx xx x xx xx xx xx xx xx xx x xx xxx m: m: w: m: :: m: 0: o: 0: mm mm mm mm mm :m mm 0m Hm om .+++++++++.+++++++++.+++++++++.+++++++++.+++++++++.xxv m.H o.H m. .o A.U.Pcoov m.m mmeHh 177 We know that the impulse response function will converge to zero (see Figure 5.5), and thus that the step response function will also converge. In light of the Monetarist proposition under consideration, we are interested in what this step response function will converge to. We can pinpoint this number as follows. Beginning with the sum of the first twelve impulse response weights, we can sum over the next 2” weights to get a single figure which will be subtracted in the step response function during the next 2H periods. We can then multiply this same figure by (-52u) to get another figure describing the total amount which will be added to the step response function in the following 2H months. Multiplying this figure 2 will then yield the total amount to be subtracted (\ by (-62u) again in the following 2H months. Continuing this procedure indefinitely would give us the exact number to which Vl(B) converges. Continuing for a few iterations will closely approximate this number. The sum of the first l2 impulse response weights = V12 = 1.u027. The sum of the next 2” impulse response weights = 1.H719. Thus, V36 = l.H027 - 1.u719 = -.0692. The sum of the following 2H impulse response weights = (l.H719)(.5583) = .8218 Thus, V = -.0692 + .8218 = .7526 60 178 The sum of the following 2H impulse response weights = (1.9719)(.5583)2 = .9588. Thus, v8” = .7527 - .9588 Continuing: <1.9719)(.5583>3 = .2561 v108 = .2938 + .2551 = (1.9719)(.5583)” = .1930 v132 = .5999 - .1930 = (1.9719)(.5583)5 = .0798 v156 = .9059 + .0798 = <1.9719>(.5583)6 = .0998 v180 = .9857 - .0995 = (1.9719)(.5583)7 = .0299 v20” = .9921 + .0299 = (1.9719)(.5583)8 = .0139' v228 = .9570 - .0139 = (1.9719)(.5583)9 = .0078 v252 = .9531 + .0078 = Hence we see that to approximately .H570. .5999 .M069 .H867 .MM21 .H870 .H531 .U609 .2938 the step response function converges This suggests that money is not neutral, but that a sustained increase in the growth rate of the money stock will produce an increase in the growth rate of Real GNP in the long run. Finally we are interested in the impulse and step response functions for the second input, BCD92, implied by 179 our model in equation (5.27). These are listed and plotted in Figure (5.7). Expanding the Model to Account for the Energy Price Supply Shocks of the Early 1970's - Fuel Prices In equations (5.25), (5.26), and (5.27), we included a second input to account for the effect of the oil crunch in 1973, and the subsequent change in the world. We used as our second input, BCD92, the percent change in the PPI of Crude Materials. This is interesting, since BCD92 is one of the leading indicators which constitute the subject of discussion of Chapter IV. However, much of the supply shock literature listed in footnote 5 uses Fuel prices in this role. Thus we now re—examine the relationships discussed in the last section, with x2t=Fuel prices. We must first consider the relationship between Fuel prices and Industrial Production. The bivariate model describing this relationship is presented below.12 BCDH7 Index of Industrial Production yt x PPI of Fuel, Power, and Related Products t Sample: May, 1950 - November, 1979 (n = 355) (A) 12 ° _ O 8 12 (l-B )(l-B)log(yt) - Fé—i—B- B (l-B )(l-B)log(xt) 1-0 812 + 12 a 1-¢1B t O (.055) 1 (.169) 12 (.033) 1 (.053) 2 —2 _ = ”1.1 RSE = .0129 R - .5775 (k).+++++++++.+++++++++.+++++++++.+++++++++. (DmflmU‘l-Fle—‘O for x2t = -.l O. ><><><><><><><><>< XXXXXXXXXXX XXXXXXXX XXXXXX XXXX XXX XXX XX XX XXXXXXXXXXXXXXXXXXXXXXXXXX><><>< 180 FIGURE 5.7 GRAPH OF IMPULSE RESPONSE WEIGHTS [v (B)] BCD92 in equation (5.27) .1 VALUES [vk] IOOOOOOOOOO O O .0 O O O O C O .103629E+00 .709052E—Ol -.H85147E-01 -.3319H7E-01 -.227lZSB—01 —.155u03E-01 -.106330E-01 -.727529E-02 —.u97789E-02 -.390597E—02 -.233093£—02 -.159u53E-02 -.109101E-02 -.7H6H87E-03 -.510761£-03 -.399H72B-03 -.239116E-03 -.163608E-03 -.1119”ME-03 -.765939E-0U -.52H070E-0H -.358579E-OH -.245397E-0u -.16787lE—0M -.llHBBlE-0M -.785898E-05 -.537727E-05 -.367923E-05 -.2517HOE-05 -.1722u5E-05 -.1l785”E-05 -.806377E-06 -.551739E-06 -.377510E-06 -.258300E-06 -.l7673hB-06 -.128925B-06 181 FIGURE 5.7 (cont'd.) "ol 0. cl (k),+++++++++,+++++++++,+++++++++,+++++++++, VALUES [vk] U7 X -.82739OE-07 #8 X -.566116B—07 182 FIGURE 5.7 (cont'd.) GRAPH OF STEP RESPONSE WEIGHTS [V2(B)] for x2t = BCD92 -.5 -.25 0. .25 (k).+++++++++.+++++++++.+++++++++.+++++++++.+++++++++.VALUES LOCDQCDU‘L'OOMF-‘O ><><><><><><><><><>< XXXXX XXXXXXXX XXXXXXXXXX XXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX 'OOOOOOODOO .103629 .17953H .223099 .2562HH .278956 .29HH97 .305130 .312905 .317383 .320788 .323119 .329713 .32580H .326551 .327062 .327411 .327650 .32781u .327926 .328002 .328055 .328091 .328115 .328132 .3281H3 .328151 .328157 .328161 .328163 .328165 .328166 .328167 .328168 .328168 .328169 .328169 .328169 .328169 .328170 -.5 182 FIGURE 5.7 (cont'd.) GRAPH OP STEP RESPONSE WEIGHTS [V2(B)] for x2t = -.25 0. .25 BCD92 (k),+++++++++.+++++++++,+++++++++,+++++++++,+++++++++.VALUES LOCDQCWWICDNHO 5:53;:4:4::wwwwwwwwwwMMMNNNMMNMHl—Ji—‘l-Jl—‘I—‘Hl—ii—‘I—J (10010301chNHocoooqmmzmeocoooqmmcwMI—‘ococo\Immscorch—Io ><><><><><><><><><>< XXXXX XXXXXXXX XXXXXXXXXX XXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXX (3000000000 0 O 0.. O 0 -.103629 -.17H53U -.223OH9 -.2562HH -.278956 -.299H97 -.305130 -.312U05 -.317383 -.320788 -.323119 -.32H713 -.SZSBOH -.326551 -.327062 -.327Hll -.327650 -.327BIH -.327926 -.328002 -.328055 —.328091 -.328115 -.328132 -.3281M3 -.328151 -.328157 -.328161 -.328163 -.328165 —.328166 -.328167 —.328168 -.328168 -.328169 -.328169 -.328169 -.328169 -.328170 183 This model shows that the Fuel PPI displays a substantial lead over Industrial Production. The last column of Table V-3 shows the monthly observations of the first log difference of the Fuel PPI, during the oil crunch of 1973. This series displays a large increase in late 1973 and early 1979. Since the Fuel PPI has a lead of eight months over Industrial Production, it may be successful in capturing the effect of the oil crunch, and thus improving the poor forecasting performance of our model in equation (5.7) during late 1979. The Identification Stage As before, with our two inputs, FMt and BCD92, we are now interested in the cross-correlation functions between the two inputs, FMt and Fuel Prices; first transformed by the prewhitening model for FMt, and second, transformed by the prewhitening model for Fuel prices. These two cross- correlation functions, r (k) and r (k), are listed o‘11"‘21 “22021 in Table V-7. Examination of r (k) shows that two coefficients “11921 are "significantly different from zero." Since we expect about 2 1/2 coefficients to vary from zero at the 95% confidence level, this cross-correlation function supports the assumption that these cross-correlations are zero. Hence the cross-correlation function between prewhitened FMt and the similarly transformed output series can be used to identify the first impulse response function in this 189 TABLE V-7 Cross Correlations: Series a11 - Prewhitened Filtered Money Supply (<521+ = -.5520) Series a12 - Prewhitened PPI of Fuel Power and Related n = 355 Products Mean of Series all = .38159E-03 St. Dev. of Series all = .99258E-02 Mean of Series a12 = .78262E-09 St. Dev. of Series a12 = .13782E-01 Number of Lags Cross Number of Lags Cross on Series all Correlation of Series a12 Correlation (k) Pa a (k) (k) ra a (k) 11 12 ‘12 22 0 .096 0 .096 l .031 l .059 2 -.053 2 -.067 3 -.037 3 -.016 9 .003 9 -.061 5 .013 5 .057 6 —.095 6 .099 7 .069 7 -.055 8 —.059 8 .036 9 .090 9 -.197 10 -.058 10 .096 11 .192 11 . -.009 12 -.035 12 -.003 13 .023 13 -.020 19 —.008 19 -.092 15 .021 15 -.102 16 -.059 16 .168 17 .056 17 -.061 18 .005 18 .021 19 -.066 19 .091 20 .109 20 -.091 21 -.072 21 .023 22 .090 22 -.021 23 -.059 23 .018 29 .099 29 -.098 25 -.096 25 .010 26 .002 26 .098 27 .010 27 -.005 28 .018 28 -.027 29 -.012 29 .107 30 .009 30 -.080 31 .062 31 -.023 32 -.025 32 -.009 33 .026 33 .058 39 -.099 39 .002 185 TABLE V-7 (cont'd.) Number of Lags Cross Number of Lags on Series all Correlation on Series al2 Correlation (k) Pa d (k) (k) ra a (k) ., ..,. 11 12 ., . ,. 12 11 35 .033 35 —.053 36 -.060 36 .059 37 .071 37 -.002 38 -.013 38 -.020 39 -.021 39 .085 90 .009 90 -.026 91 .039 91 -.079 92 —.019 92 .055 93 -.068 93 -.023 99 ' .015 99 .017 95 .021 95 -.062 96 .018 96 .082 97 -.051 97 -.039 98 -.079 98 .018 Prewhitening: (1-.8681B)(1—.2l90B-.3091B3)(1+.6101B12)[FMt] = (1+.1169B-.1397810—.181081”)a t -. same model on (1-B12)(1—B)log[Fue1 PPI]. 186 TABLE V-7 (cont'd.) Cross Correlations: Series a22 - Prewhitened PPI of Fuel Power and Related Products Series a21 - Prewhitened Filtered Money Supply (629:'-’5520) Mean of Series a22 = .77038E-03 St. Dev. of Series a22 = .96629E-02 Mean of Series a21 = .56007E-02 St. Dev. of Series a21 = .78979E-02 Number of Lags Cross Number of Lags Cross of Series a22 Correlation on Series a21 Correlation (k) r . (k) (k) r (k) “22921 o‘21"‘22 0 -.000 0 -.000 l .095 1 -.029 2 -.005 2 -.092 3 -.078 3 -.069 9 .091 9 -.018 5 .005 5 -.021 6 -.091 6 -.031 7 -.032 7 .009 8 .001 8 .070 9 -.088 9 .005 10 -.020 10 .092 11 ' -.098 11 .166 12 -.038 12 .057 13 .039 13 .086 19 -.098 19 .086 15 -.070 15 .098 16 .111 16 .069 17 -.029 17 .096 18 .002 18 .055 19 .022 19 .057 20 .019 20 .191 21 -.009 21 .000 22 .018 22 .119 23 -.017 23 .079 29 .029 29 .069 25 .066 25 .031 26 .070 26 .061 27 -.007 27 .039 28 .099 28 .029 29 .050 29 .038 30 .003 30 .059 31 .003 31 .069 32 .063 32 .053 33 .026 33 .022 .066 00 4‘: 39 .003 187 TABLE V-7 (cont'd.) Number of Lags Cross Number of Lags Cross of Seriesa22 Correlation of Series a21 Correlation (k) ra a (k) (k) Pa a (k) 22 21 21 22 35 —.009 35 .099 36 .069 36 .027 37 .098 37 .075 38 -.006 38 .090 39 .029 39 .013 90 .105 90 .008 91 -.095 91 .003 92 .033 92 .003 93 .018 93 -.039 99 .021 99 -.003 95 —.000 95 —.039 96 .011 96 .035 97 -.039 97 -.036 98 .098 98 -.098 Prewhitening: (1-.6606B)(l-Bl2)(1-B)1og[Fuel PPI] = (1-.8923812)at - same model on levels of FMt' 188 two-input transfer function. An examination of r (k) also shows two “22921 coefficients which vary from zero. Analagously, we can use the cross-correlations between prewhitened Fuel prices and the similarly transformed output series to identify the second impulse response function in this two-input transfer function. The Estimation Stage We are now ready to redevelop equations (5.25), (5.26), and (5.27), with Fuel prices as our second input.13 yt = BCD97 Index of Industrial Production x1t = FMt = Filtered Mt as in (5.6),w1th 62u=-.9920 x2t = PPI of Fuel, Power, and Related Products Sample: May, 1950 - September, 1973 (n = 281) (0 (5.25)' (1-B12)(l-B)log(yt) ° 2” [xlt] 1—6 B 29 w' 8 1 O + 1-618 B (l-B 3(1—8)1og[x2t] 1-0 812 + 12 a ‘1:$IS“ t . w = .1928 52l+ = -.9917 w; = -.0890 5i = .8882 (.051) (.260) (.073) (.131) e = .8059 ¢ = .2537 12 (.090) l (.063) X36 = 39.2 RSE = .0135 82 = .5373 A comparison of these parameter estimates with those in equations (5.25) through (5.27) shows that the parameters, 189 A and 01 are quite stable as we change from A, A “o ’ 529’ 12’ BCD92 as our second input, to Fuel prices. A comparison of 6 the parameters 05 and Si with the coefficients in the single- input transfer function with input, Fuel prices (on page 179Lshows that the form of this impulse response function is also quite stable when the second input, FMt’ is added. We are interested in how this model will forecast over the next 18 months, through the oil crunch. Table V-8 shows these 18 one-step-ahead forecasts. Comparison with Table V—3 shows much improvement in reducing the forecast errors appearing in late 1979 in our single-input model. Comparison with Table V-5 shows that Fuel prices are more successful in reducing these forecast errors in late 1979 than is BCD92. The Theil Decomposition statistics support this finding. We now proceed to re-estimate equation (5.26) with Fuel prices as our second input.lu BCD97 Index of Industrial Production yt : x1t = FMt = Filtered Mt as in (5.6), With 62u=«-.9600 x2t = PPI of Fuel, Power, and Related Products Sample: May, 1950 - March, 1975 (n = 299) , 12 “o (5.26) (l-B )(1—B)log(y ) [x 1 t 29 1t 1-5 B 29 w' 8 12 o + 1_61B B (l-B )(l-B)log[x2t] 1—0 812 + 12 a t 1-¢1B 190 Mmz mo wu.mm u onwm:o.0 u 0: mm: mo wm.0 u mammmo. n m: mmz mo wm.o u mzaaao. n z: mam:m:.a u mmzm m ::omHH.0 n mm: HAD. 0 mmmm.mma n l ummmma.a u m mom mm. 000.H o.maa m.:HH o.moH :Nm.HHH H.mb 0mm 5H. nma. w.HHH m.:HH n.moa mHm.HHH 0a.:b mmm 00.m| 3m:.m| m.:HH m.HOH m.mHH 0mm.maa HH.:> mmm w>.Hn mom.0| m.m0H H.Hma :.:0H mo>.00H oH.:n :mm 00.: 3mm.) 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We want to examine this model's ability to forecast over the next 9 1/2 years. These 56 one-step-ahead forecasts appear in Table V-9. The forecast errors indicate that this model performs quite well over this long forecast horizon, and the Theil Decomposition statistics Show marked improvement over previous models. Hence we proceed to the last step and re-estimate equation (5.27) with our new second input, Fuel prices.15 yt = BCD97 Index of Industrial Production x1t = FMt = Eiltered Mt as in (5.6), With - -.5520 29 x21: = PPI of Fuel, Power, and Related Products Sample: May, 1950 - November, 1979 (n = 355) (A) (5.27)' (l-B12)(l-B)log(yt) = O 29 [ l-62uB J xlt “5 8 12 I:XI§ B (l-B )(1-B)1og[x2t1 + 12 1-612B 1-¢1B t 192 HH.I m:H.I H.:ma 3.0mH m.oma m:0.:ma m.n> mmm Ho. mac. m.H:H H.m:H m.>ma mm:.H:H m.3b mmm mm.) mm:.| 0.0ma 0.H:H 0.:mH mmm.bma :.00 :mm m>.| mmo.Hn 0.mma m.o:a m.mmH mm0.>ma m.>h mmm 03. mon. >.mma m.mmH m.HmH mmm.:mH 0.00 00m :0. mmo. m.mma c.3mH 0.oma w:m.mmH H.5b Hum mm.n m30.H m.mma :.mma m.m0H who.oma 03.m> 00m 30.: mHo.| m.mma m.HmH H.m0H mam.mma HH.mb mam m3. 03m. 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