Publications
Race, immunity, and lifespan: Unraveling the effect of early-life exposure to malaria risk on lifespan
Economics and Human Biology, 54, 101382. 2024. (with Sok Chul Hong) [Link]
Abstract
We investigate a historical experience to measure the long-term effect of malaria on lifespan among infected survivors and identify a factor that mitigates malaria’s effect. Using a sample of Union Army veterans born during the mid-19th century and their lifetime records, we show that exposure to high risk of malaria at birth or in early life substantially shortened their lifespan. The legacy of exposure to malaria is robust while controlling for lifetime socioeconomic and health conditions, fixed effects, and considering selection bias. Additionally, we include the US Colored Troops sample of black veterans to analyze racial differences in the effect of malaria exposure on lifespan. Exposure to malaria did not lead to a shorter lifespan among black veterans. Evidence suggests that genetic immunity to malaria in black veterans might contribute this heterogeneity.Mortality, Nutrition and Height in Early Colonial Korea
Review of Economic History, 67(2), 197–225. 2018. (in Korean) [Link]
Abstract
The determinants of stature can be changed in one country by the change of cultural and economic situation. The cases of western countries in 19th century are good example. Therefore, identifying the determinants is needed to understand the change of stature in colonial Korea. In this study, I used Prisoners’ cards made in prions that provide a lot of information about their characteristic. What I found is that disease environments were important factors to determine people’ stature in early colonial Korea. The change of the mortality rate that reflected disease environment explained the statural change. I analyzed influence of disease environment by year. There is no difference in the coefficient by year. The implication of this study is to identify factor determining statures in early colonial Korea.Working Papers
(Job market paper) Avoiding the Risk, Bearing the Cost: Evidence from General Health Screening in Korea during the COVID-19 Pandemic
submitted (with Sok Chul Hong) [PDF]
Abstract
This study examines the unintended health consequences of voluntary responses to COVID-19. We focus on general health screening in Korea, using administrative data linking medical claims and screening records. We find that screening rates declined sharply in 2020 relative to counterfactual trends, particularly among individuals at higher risk of chronic diseases. Next, we assess the effect of forgone screening using propensity score matching and event study designs. Our estimates show that individuals who missed screening would have been more likely to initiate care for chronic diseases if screened. Such delays in management lead to more advanced conditions at care initiation.The National Immunization Program for Children Expanded: Its Impact on Influenza Vaccination and Healthcare Use
[PDF]
Abstract
This study examines the impact of expanding the eligible age for child influenza vaccinations in Korea. To control for time trends in influenza vaccination rates, I estimate a difference-in-differences model using children not affected by the age expansion as a control group. Through this model, I find that expanding the program's eligible age significantly increased the vaccination rate of children aged 5-12 in the treatment group. This increase is mainly observed among households with incomes above the median, those with working mothers, and those living in areas with high access to healthcare facilities. Next, I use National Health Information Database from the National Health Insurance Service (NHIS) to analyze changes in influenza-related healthcare utilization as the program's eligible age expanded. The results show that the estimates from the difference-in-differences model are not robust to time-varying confounding factors related to influenza incidence. To address this, I estimate a triple difference model that exploits temporal variation in the match between the influenza vaccine and prevalent viruses. The results show that influenza-related healthcare utilization decreased during periods of high match rates after the policy was implemented.Works in Progress
Impact of Negative News about Covid-19 Vaccine on Vaccination
(with Sangbeom Kim, Dae-il Kim, Sok Chul Hong)
Abstract
Informed decision-making is a fundamental mechanism within society, exemplified by vaccination choices. During the global COVID-19 pandemic, vaccination emerged as a crucial strategy for mitigating societal risks, yet uncertainty surrounding vaccine side effects persisted. This uncertainty is often exacerbated by the overwhelming volume of information available, leading individuals to selectively engage with preferred news narratives. This study examines the impact of exposure to negative information about vaccines on vaccination rates in South Korea. Our findings reveal a strong correlation between support for government vacc ination policies and individuals' political affiliations: those aligned with the government are more likely to endorse these policies, while opposition supporters tend to resist them. This trend arises from a preference for news sources that present negati ve content opposing official government views. To test this hypothesis, we employ text analysis to explore differences in coverage of "COVID-19 Vaccination" by conservative and liberal news outlets, revealing a pronounced negativity in reporting from certa in sources. Furthermore, by measuring exposure to conservative news outlets and analyzing regional variations prior to the pandemic, we demonstrate significant disparities in vaccination rates linked to the political orientation of news consumption. These results highlight the critical role of negative vaccine information in shaping public health decision-making.The Impact of Wedding Restrictions on Non-Marital Births during COVID-19: Evidence from South Korea
(with Dae-il Kim, Sok Chul Hong)