Today, users of mobile devices (smartphones and tablets) adopt a variety of apps, use social features, and engage in crowdsourcing content as a public good. This dissertation explains their user community, i.e., a mobile virtual community, in terms of user contribution and its social-welfare value around urban areas. Essay 1 conceptualizes a virtual and spatial factor, i.e., virtual crowdedness, and addresses its role in encouraging user contribution. The findings are theoretically explained... Show moreToday, users of mobile devices (smartphones and tablets) adopt a variety of apps, use social features, and engage in crowdsourcing content as a public good. This dissertation explains their user community, i.e., a mobile virtual community, in terms of user contribution and its social-welfare value around urban areas. Essay 1 conceptualizes a virtual and spatial factor, i.e., virtual crowdedness, and addresses its role in encouraging user contribution. The findings are theoretically explained by the tension between prosocial behavior of and bystander effect on the mobile virtual community. Essay 2 theorizes whether and how user contribution, attributed to self-interest, supports social welfare for the whole citizenry. I found that user contribution improves the mobility of urban transportation and reduces social and economic costs. As an exemplar of citizen-data science, this dissertation takes a spatial and panel data approach to analyze the large-scale data on mobile app users, traffic conditions, and their locations in the urban region. The empirical findings are visualized and discussed to explain practical implications for mobile app design and policy on urban transportation. Show less
