<p dir="ltr">This dissertation consists of three chapters on economic topics related to spatial, macro, and international economics. In the first chapter, I develop a dynamic spatial general equilibrium model with overlapping generation in which heterogeneous individuals accumulate human capital and move across states. Calibrated to the 2000 U.S. economy, the model illustrates how variations in education efficiency lead to substantial cross-state income disparities and shows that internal migration can notably boost output in states with lower education efficiencies. Applying the calibrated model to analyze the Obama Administration's Race to the Top initiative finds that the initiative increased the U.S. GDP, benefiting the grant-winning states and their neighbors. Strategic reallocation of education grants could further increase national GDP gains without necessarily worsening state income disparities.</p><p dir="ltr">The second chapter of this dissertation is coauthored with Dr. Soojin Kim and Dr. Chong Xiang. We investigate how the China shock affects workers’ health through optimal health investment decisions. We empirically estimate the elasticity of import penetration per worker on future good health probability. In our quantitative evaluation of the China shock, we find that there is little (substantial) change in the probability of future good health of employed workers whose health is initially bad (good), in line with our empirical estimates. In our counterfactuals, we find that universal health insurance would have remedied most of the adverse health effects from the China shock, with large heterogeneity across sickness shocks and across commuting zones with varying degrees of exposure to import penetration.</p><p dir="ltr">The last chapter of this dissertation is coauthored with Dr. Seungyub Han, using regional level data of South Korea. We analyze the effect of conventional land-use restrictions in existing cities as well as the impact of building new cities on undeveloped rural regions, motivated by the South Korean government's 2nd New Town Project (NTP). We estimate the effect of such policies on the aggregate and regional economies, considering both the efficiency gain from the resource reallocation and externalities from regional decline. Our quantification suggests that the NTP promoted economic growth cost-effectively, as it permanently increased the steady state real GDP flow for a one-time building cost. However, it exacerbated regional decline by significantly decreasing the overall rural population.</p>