I estimate the effects of pro-natalist cash transfers on fertility, sex ratio at birth, and infant health in South Korea, using registry data from 2000–2015. I find that the total fertility rate in 2015 would have been 4.7 percent lower without the transfers. Cash transfers also lowered the sex ratio at birth, historically skewed toward boys in South Korea. Additionally, I show that the cash transfers led to reductions in birth weight and gestational length, which appear to be driven by negative selection into fertility, and that the cash transfers may have had positive impacts on birth weight among low-income families.
We study how industrial robots affected human capital investment during high school. Using Texas administrative records for 2004–2018 and an instrument based on European robot adoption, we find that greater local robot exposure reduces dropout and increases observed high school completion. Students also shift coursework toward college preparation and away from vocational subjects. Advanced course enrollment rises throughout high school, while dropout reductions and additional math, science, and technology coursework are concentrated in the upper grades. Both boys and girls increase academic investment, but the implications for gender gaps differ: some differences in subject enrollment narrow, while girls’ larger gains in advanced coursework reinforce their existing advantage. These patterns suggest that students respond to changing local labor demand by strengthening their preparation for further education. Human capital formation is therefore an early margin of adjustment to automation, shaping the skills of the workforce that will face its longer-run consequences.
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 the unintended consequences of South Korea's 2008--2010 immigration reforms for marriage markets and native households. The reforms expanded work and residency opportunities for ethnic Korean Chinese migrants, reducing reliance on marriage-based entry. Exploiting pre-existing variation in sex ratios and marriage-migrant networks in a DDD design, we find substantial reductions in marriage migration and marriages between Korean men and foreign women, alongside increased work migration. Among native couples whose marriages predate the reforms, wives' employment-decision autonomy rises by 0.36 standard deviations, employment increases by 9 percentage points, and market work rises by five hours per week. Household income and expenditures increase, subjective well-being improves, and divorce falls by 16 percent, with the decline concentrated in divorces attributed to irreconcilable differences and the share attributed to psychological or physical abuse rising. The results show how immigration policy can reshape marriage-market conditions and affect bargaining, behavior, welfare, and marriage stability.
We study how automation affects internal migration in a labor-scarce economy. A stylized framework shows that task-level substitution need not imply local contraction: when routine labor is scarce, automation's expansionary effects on local labor demand can outweigh displacement. Using South Korean data and a long-difference design with shift-share robot exposure, we find that greater robot exposure increases job-related net migration but not non-job-related migration. Robot exposure is also associated with higher wages, expansion in employment categories associated with complementary activities, and manufacturing establishment growth. Consistent with the framework, the job-related migration response is substantially larger in tighter baseline manufacturing labor markets. We then compare automation with an independently generated immigration shock. Both shocks increase job-related native migration, remain similar when included jointly, and show little evidence of systematic amplification or attenuation. The findings suggest that both automation and immigration can facilitate local adjustment to labor scarcity by attracting workers rather than displacing them.
How does partisan media affect political extremism? Partisan slant bas been shown to polarize voting behaviors and attitudes. Yet, we know little about how it affects extremist activity outside the election system, such as hate crimes. To address this gap, we leverage the staggered expansion of Sinclair Broadcasting Group, a conservative media company, as a natural experiment. Because of its conservative slant, Sinclair's programming raises concerns about increased negative portrayals of certain social groups. In Study 1, we estimate Sinclair's effect on hate crimes using an event study design. In Study 2, we analyze local newscast transcripts to assess whether and how news content discussing specific vulnerable groups differ between Sinclair-owned and non-Sinclair-owned television stations using sentiment analysis and contextual embeddings-based metaphor analysis. Our findings show that Sinclair's entry into a local media market increases hate crimes by an average of 0.5 per 100,000 residents, with this effect persisting for five years post-entry. The most affected victims are targeted based on their sexual orientation, race/ethnicity, or religion. Additionally, Sinclair's entry is associated with a higher share of negative stories and increased use of anger, fear, and disgust-related words in media coverage on Muslims and Islam. Lastly, Sinclair-owned stations generally exhibit higher levels of dehumanizing metaphor use compared to non-sinclair-owned stations.
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.
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.