Essays on urban agglomeration economies

This dissertation comprises three self-contained essays on urban agglomeration economies. The first essay studies the optimal population agglomeration in a city in dynamic contexts. The second essay tests the local labor market agglomeration economies in the Boston metropolitan area, focusing on the effects of social interactions at workplaces on individual earnings. The third essay tests the effects of social interactions at residential locations on housing values.; Chapter 1, "Dynamic Henry George Theorem and Optimal City Sizes", extends the static Henry George Theorem (HGT) to dynamic settings. Through a series of simple dynamic models, we tentatively conclude that the HGT holds in dynamic models in terms of present values. In economies with congestion or production externalities, the dynamic HGT still holds if externalities are correctly priced.; Chapter 2, "Smart Cafe Cities: Testing Human Capital Externalities in the Boston Metropolitan Area", uses the 1990 Massachusetts census data and tests four types of human capital externalities at the microgeographic levels in the Boston metropolitan area labor market: depth of human capital stock, Marshallian labor market externalities, Jacobs labor market externalities, and thickness of the local labor market. We find that all types of human capital externalities are significant across census blocks. Different types of externalities attenuate at different speeds over distances. For example, the effect of human capital depth decays rapidly beyond three miles away from a block centroid, We conclude that knowledge spillovers are very localized within a microgeographic scope in cities that we call, "Smart Cafe Cities."; Chapter 3, "What Has Been Capitalized into Property Values: Human Capital, Social Capital, and Cultural Capital?", classifies three types of social-interaction-based social amenities: human capital, social capital, and cultural capital at residential neighborhood levels. We use the 1990 Massachusetts census data and estimate hedonic housing models with social amenities. The findings are as follows: (1) Human capital has significant positive effects on property values. (2) Different types of social capital have different effects on property values: an increase in the percentage of new residents has significant positive effects on property values, probably due to the strength of weak ties. However, an increase in the percentage of single-parent households has negative effects on property values. (3) Cultural capital's effects vary from high to low geographic levels, the effects of English proficiency and racial homogeneity are positive at and beyond the tract level, but insignificant at the block level.