Research

We study employment outcomes during the early stages of the COVID-19 pandemic across eight countries exhibiting different case levels and policy responses: the United States, Australia, France, Denmark, Italy, South Korea, Spain, and Sweden. While the proportion of people not-at-work increased in all countries, safety net policies seem to influence whether people remained employed-but-absent from work as opposed to becoming unemployed or leaving the labor force. We find large employment decreases among young workers and those who only have a high school degree, and increased labor market disparities in countries with the largest declines in employment. A variety of evidence suggests labor demand was a larger driver of employment declines than labor supply and that stringent social distancing policies reduce employment even in the absence of high case numbers. Job characteristics - the importance of face-to-face interactions and the ability to work remotely - were closely related to changes in labor market outcomes.

This study examines the impact of in utero exposure to ambient particulate matter (PM) on neonatal health outcomes, utilizing comprehensive population-level birth records from South Korea for pregnancies between 2016 and 2019. To address potential endogeneity concerns, the analysis adopts wind direction as an instrumental variable for prenatal PM exposure. The findings indicate that exposure to PM during the first trimester significantly increases the likelihood of preterm birth, and this effect remains robust across a range of model specifications. Moreover, the estimated impacts are consistent across different socioeconomic strata. These results highlight the critical importance of environmental health during early pregnancy and suggest that in low-fertility, late-childbearing societies such as South Korea, environmental protection efforts should be closely aligned with maternal health policies. 

I explore the causal effects of single-sex high schools on long-term labor market outcomes using a unique feature of educational policy in South Korea—the random assignment of students to single-sex versus coeducational high schools. I find that the effect of single-sex schooling on earnings is positive for women but not for men. The effect varies with job experience, increasing by 1.9 percentage points with each additional year of experience. In addition, single-sex schooling affects other labor market outcomes, including women's work hours and job satisfaction. Finally, I use measurements of completed education and job training as human capital accumulation to study potential mechanisms for gender differences in the effect of single-sex schooling.

We estimate the causal effect of ambient air pollution on early-life health and medical care utilization among children ages 0–12 in South Korea by linking National Health Insurance Service (NHIS) claims data from 2008–2018 with monitor-based pollution measures. To address endogeneity, we use a two-stage least squares strategy exploiting variation in westerly winds that transport dust and industrial emissions into Korea. Higher particulate concentrations increase pediatric respiratory morbidity and covered medical spending, with effects concentrated among children ages 0–6. Evidence from the Korea Health Panel Study (KHPS) shows no corresponding change in non-covered medical spending. Complementary evidence from the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) indicates that the respiratory response is primarily driven by children attending childcare facilities.

We study the fertility effects of central and local pronatalist cash transfers in South Korea. Using population-wide administrative records from the National Health Insurance Service, we exploit sharp eligibility and announcement cutoffs from the 2023 expansion of the universal Parental Allowance and estimate short-run effects using a regression-discontinuity difference-in-differences design. We find declines in births at thresholds, with larger effects among older and lower-income women, and no evidence of short-run adjustments in birth order or delivery type. Local lump-sum baby bonuses generate modest fertility gains, concentrated in non-capital areas and driven by parity-specific bonus schedules rather than broader quasi-cash benefits.

As aging societies face rising claims on public budgets, governments increasingly confront the question of whether to reparameterize statutory fiscal rules. We use a nationally representative survey experiment with 3,066 Korean adults to test whether concise information can shift public support both for overall education-spending levels and for the underlying allocation rule: Korea's Local Education Finance Grant, which statutorily earmarks 20.79% of domestic tax revenue. Three information treatments, emphasizing expenditure efficiency under demographic change, international benchmarks, and cross-sector budget trade-offs, each lower the preferred education share by 2-3 percentage points. The same treatments shift perceived adequacy of both the education budget and the 20.79% earmark toward "too generous" and redirect preferences over the use of any fiscal surplus. Belief updating is concentrated among respondents previously unaware of the LEFG. A supplementary survey of 44 public-finance experts provides an external benchmark: across the core margins, information moves public preferences toward the expert consensus rather than toward arbitrary retrenchment. The findings suggest that concise, neutral information can discipline public preferences over both the level and the perceived generosity of an entrenched fiscal earmark, a margin likely to matter in other aging economies with rigid statutory transfers.

Whether maternity leave raises fertility depends on which margin of leave matters: the wage replacement that cushions time off, or the job protection that preserves employment continuity. Using the NLSY97, this paper estimates the within-person relationship between employer-provided maternity leave and fertility timing among employed U.S. women, with leave access dated near conception, and, unlike the administrative-data designs that anchor the recent U.S. family-leave literature, it separates unpaid from paid leave at the worker level. Lagged unpaid-leave access is associated with a 2.3 percentage-point higher annual probability of childbirth, concentrated on the first birth, while the paid-leave coefficient is small and noisy when pooled but positive and statistically significant on the first-birth margin. A within-job wage decomposition rules out a compensating wage penalty larger than about $0.15 per hour. A mediation analysis attributes about one-quarter of the Graduate-HS childbirth gap to differential leave access, almost entirely through unpaid leave, though the preferred fixed-effects estimates do not reject homogeneity across education groups. The unpaid-paid contrast points toward an employment-continuity interpretation rather than a wage-replacement one, though the data do not directly measure the underlying margins. The within-person evidence complements recent administrative-data studies of U.S. paid-leave expansions, which find little effect on aggregate fertility. Because the cohort is observed only through age 35, the estimates are best interpreted as associations with fertility timing rather than with completed fertility.

This paper revisits a matched-comparison study of in-service teacher training in 12 Jerusalem elementary schools, using machine-learning estimators of conditional average treatment effects to describe the distribution of estimated gains among 648 pupils. The estimates are suggestive of heterogeneity by prior reading achievement: pupils below the sample median appear to gain about 0.56 standard deviations, while higher-scoring pupils show no measurable gain; a linear treatment-by-covariate interaction does not reproduce this pattern. Across many random school splits, school-level targeting delivers unstable out-of-sample gains centered close to zero. The findings extend machine-learning reanalyses from average effects to the shape of estimated heterogeneity

Using data from the Korean Labor and Income Panel Study (KLIPS), this paper tests four hypotheses on the source of the marriage premium for South Korean men and women: the selection, productivity, specialization, and favoritism hypotheses. Fixed effects regression results show that men experience a significant marriage premium, while women face a significant marriage penalty, resulting in a significant gender differential in the returns to marriage. Our results are generally consistent with all four hypotheses, with the selection and favoritism hypotheses receiving stronger support than the productivity and specialization hypotheses. We conduct instrumental variable estimation throughout our analyses using the zodiac sign of the birth year to test the endogeneity of marital status, presence of children, and spouse’s labor activities, all of which are subsequently suggested not to be endogenous.

This study empirically analyzes the effect of the 2021 increase in charitable contribution tax credit rates on taxpayers' donation behavior. Previous studies in Korea primarily focused on the shift in tax treatment methods for donations, but research on the effects of subsequent changes in tax credit rates has been limited. Using a balanced panel sample of income tax filers from 2018 to 2022, constructed from income tax return and donation statement data of taxpayers who filed global income tax or wage income tax year-end settlements, this study applies the difference-in-differences method to assess how the 2021 tax credit rate increase influenced charitable giving amounts and participation rates. The findings indicate that, for global income taxpayers, the average donation amount increased following the policy change, particularly among middle-income groups. This increase is largely attributed to greater participation by new donors and the growth of small-scale and non-religious donations. Conversely, wage earners exhibited a decline in both average donation amounts and participation rates despite the tax credit increase, with high-income earners experiencing the most substantial reductions. These tax credits appear to result from interactions with other expanded tax credits, such as those for credit card spending. The results highlight the differential impacts of tax credit changes by income group and taxpayer type, underscoring the importance of considering these differences and policy interactions when designing future charitable giving incentives.

This paper investigates the enforcement effects of the “Law on the Improvement of the Mobile Terminal Distribution System (Mobile Terminal Distribution Act),” which was implemented in October 2014. Despite the nationwide attention to the legislation, an empirical analysis of the market effects of the Mobile Terminal Distribution Act is yet to be done. Using a rich dataset obtained from handset retail stores authorized by telecommunication agencies, we perform both an ordered probit MLE and a panel regression. We find the following facts. First, Mobile Terminal Distribution Act has effectively enabled consumers to choose less expensive plans. The reduced amount of subsidy for handset purchases seems to be the main reason for this phenomenon, as Mobile Terminal Distribution Act originally intended. Second, we find no statistically significant reductions in the prices of newly launched handsets. While the prices of some products have actually dropped, our analysis shows that it is not due to the implementation of the Mobile Terminal Distribution Act. 

This project examines the differential effect of school quality on academic achievements within and between school districts in South Korea. Exploiting the unique educational system and datasets of school characteristics in South Korea, I find that school quality has a positive effect on academic achievement and that its magnitude is much larger for students with low-level previous test scores. Under the random assignment system, this paper suggests that study-related facilities and additional chances to study after regular classes are important factors in improving students’ performance in addition to the traditional school quality measurements (e.g., teacher-pupil ratio and financial spending by school). Once the random assignment is relaxed, I can find a positive relationship between school quality and student background or “ability”. Though exploiting limited individual-level data, this paper supports the argument that high-quality schools attract more students (whether they have increased ability or not) and construct network formation through which the effect of school quality on academic achievements becomes stronger. 

The income elasticity of health expenditure calibrates fiscal and workforce projections, yet its measurement turns on how cross-country co-movement is modelled and whether financing channels are pooled. On a constant 169-country panel, 2000-2024, holding sample and estimand fixed, we vary common error dependence. Our primary finding is a financing-scheme reversal: within the country, the government-out-of-pocket margin never separates, yet factor-robustly, the government channel is near unit-elastic at 0.84, out-of-pocket at 0.29. Modelling that dependence lowers the aggregate from above one to roughly one-half, consistent with common-factor loading into the income gradient rather than mechanical attenuation. In a scenario projection, pricing the public line at the aggregate understates the 2060 high-income government-financed health share of GDP by 1.53 percentage points. What public budgets must price turns on dependence and channels, not merely the standard errors.