We study the spatial dispersion of gender and racial wage gaps across U.S. cities. First, we document substantial geographic dispersion in both wage gap measures across U.S. metropolitan areas, and show that cities with larger gender wage gaps also tend to have larger racial wage gaps. Second, we build a model of worker and firm location featuring group-specific Nash bargaining over wages and task bundles in production. The key implication of the model is the log-linear wage structure which motivates a three-way fixed-effects decomposition of wages into worker, firm, and city components, an extension of the standard AKM model, which we estimate using matched employer-employee data (Longitudinal Employer-Household Dynamics). Even after absorbing worker and firm heterogeneity, the same city offers different returns to different groups: group-specific city fixed effects account for 15.8 percent of the spatial variance in the wage gap. Our findings suggest that place is an independent determinant of gender wage inequality, and that understanding spatial variation in local labor market conditions is essential for explaining the persistent wage gap across different groups of workers
We study how robot adoption affects internal migration—distinguishing between job-related and non-job-related moves—in South Korea, an economy characterized by rapid automation alongside population aging and labor shortages. Using a long-difference design and a shift-share IV strategy, we find that robot exposure increases job-related migration but not non-job-related migration. Robot adoption raises employment, wages, and firm entry in manufacturing and generates spillovers to services, while leaving local amenities unchanged. We also show that robots and immigration independently increase job-related migration and do not substitute each other. Overall, robot effects are context-dependent and shaped by local economic conditions, including low-skilled labor-supply constraints.
We examine the consequences of South Korea's 2008-10 immigration reforms on the marriage market and intra-household outcomes. By expanding alternative migration pathways for ethnic Korean Chinese (EKC) women, the reforms unintentionally reduced the availability of foreign brides and tightened local marriage markets. Exploiting regional variation in exposure to the reforms and using uniquely rich data—administrative records, household surveys, and divorce registries—we document a marriage-market shock after the reform, measured by a drop in new marriages and EKC women on marriage visas. We then trace the reform's effects on native couples' intra-household outcomes. Women's bargaining power increased, their time allocation shifted from housework to employment, household income and spending on children's education rose, and both spouses' subjective well-being improved. The number of divorces also fell, with a shift from general incompatibility to abuse-related grounds. These findings reveal the immigration reforms' unintended impacts on household dynamics and broader economic implications.
We study the impacts of childbirth on maternal mental health and the role of pro-natalist cash transfers. Using claims-level data from South Korea's universal healthcare system, we find that mental health diagnoses rise by 34.8% (198.7%) after the first (second) birth. We find little evidence that cash transfers mitigate these effects. As potential mechanisms, we examine liquidity constraints, labor market changes, time use, and social stigma. Lastly, we document that poor mental health after childbirth is negatively associated with the likelihood of having another child.
I present novel causal evidence on the effects of pro-natalist cash transfers in South Korea on fertility, the sex ratio at birth, and infant health. I exploit rich spatial and temporal variation in pro-natalist cash transfers and the universe of birth, death, and migrant registry records. The total fertility rate in 2015 would have been 4.7% lower without the cash transfers. Surprisingly, the cash transfers had the unintended consequence of correcting the unnaturally male-skewed sex ratio and lowering gestational age and birth weight. Negative selection into childbearing may explain these effects.
In this paper, we exploit a series of the relocation of public-sector entities in South Korea as an exogenous source of variation in public sector employment to estimate local employment multiplier. We find that an introduction of 1 public sector employment increases the private sector employment by 1 unit, almost completely driven by the service sector. In line with the literature, we document that the effect of public employment on private employment is highly localized. In addition to changes in private employment, we also find that the relocation led to a positive net-inflow of residents into the treated neighborhood; this effect is also localized. Lastly, we estimate heterogeneous local employment multiplier and provide evidence that this heterogeneity is shaped by the size of public sector shocks, different types of relocation, and the extent of migratory responses.
This chapter reviews the literature on the causal effects of policies on fertility. It focuses on evidence from experiments and quasi-experiments in low fertility contexts, including studies from Europe, Northern America, Oceania, and Asia. Making no a priori restrictions on policy type, the review encompasses evaluations of parental leave, childcare, health insurance, and financial incentives such as child transfers. Childcare expansions increase completed fertility. Financial incentives had positive effects on fertility across contexts, both in the short and long run. Expansions of parental leave rights in Central Europe and the introduction of parental leave in the U.S. also had positive effects. The distributional effects of these policies are very different, with parental leave compensation benefiting high-earning couples, while expansions of childcare programs had potential to reduce social inequalities. Publicly funded contraception and assisted reproduction can reduce fertility in young adulthood and increase fertility for women over the age of 35.
We study optimal dynamic lockdowns against Covid-19 within a commuting network. Our framework integrates canonical spatial epidemiology and trade models, and is applied to cities with varying initial viral spread: Seoul, Daegu and NYC-Metro. Spatial lockdowns achieve substantially smaller income losses than uniform lockdowns, and are not easily approximated by simple centrality-based rules. In NYM and Daegu—with large initial shocks—the optimal lockdown restricts inflows to central districts before gradual relaxation, while in Seoul it imposes low temporal but large spatial variation. Actual commuting responses were too weak in central locations in Daegu and NYM, and too strong across Seoul.