Dissertation Defense: “Essays in Applied Economics," Jahyeon Koo

Date and Time


Jahyeon Koo, University of California, Santa Barbara


Jahyeon is a PhD Candidate in the Department of Economics at UC Santa Barbara. His research focuses on Demographic economics and Applied Microeconomics (Education, Labor) related to socio-economic inequality and gender gap. Prior to attending UCSB, he received a Bachelor of Arts in International trade from Pusan National University and a Master of Arts in Economics from both Seoul National University and UC Santa Barbara.

Event Details

Join us to hear Jahyeon’s Dissertation Defense. He will be defending his dissertation, “Essays in Applied Economics”. To access a copy of the dissertation, you must have an active UCSB NetID and password.


This dissertation consists of three essays. The first essay documents an empirical study of how the growth of imports from China changes post-secondary education decisions in Korea. As China has become “the world's factory'', the availability of low-skilled jobs has become worse in countries that import products from China.  I exploited cross-industry and cross-local labor market variations in import growth from China to investigate how Korean students' post-secondary education decisions were influenced by more intensive import competition from China. Using administrative statistics from high schools between 2000 and 2015, I found that in regions more affected by Chinese imports, more students pursued a college degree after finishing high school. Consistent with the enrollment pattern, I found that in Korea, a surge in Chinese imports caused huge job losses especially for low-educated workers, which decreased the opportunity cost and increased the marginal benefit for college education. However, there is heterogeneity in the enrollments based on gender and type of educational institution. In the more affected regions, male students tended to enroll in 4-year universities rather than 2-year colleges while female students were more likely to choose 2-year colleges. The findings of this study suggest that negative social norms and smaller employment loss for working women led to a more limited increase in educational investment among women.

The second essay recounts an investigation into how parents change child-related investments in rural China after the introduction of a pension program which provides them with an alternative to adult children as a source of support. Exploiting regional variation in the timing of the New Rural Pension Scheme (NRPS) in China, I found that parents who enrolled in the NRPS spent more on their children's education. Specifically, the increase in educational spending is observed for the parents of sons. In terms of the quantity of children, although the effect on the probability of giving birth to a baby is not statistically significant, I found that parents enrolled in NRPS were more likely to give birth to a boy. Considering the introduction of a pension scheme as lowering the price for future incomes, this implies that the income effect is larger than the inter-temporal substitution effect leading to higher investments in their children. Moreover, these results suggest that NRPS does not weaken son preference in China, although this program can provide old-age support for parents instead of sons who traditionally did this.

The third essay revisits literature estimating the effect of unilateral divorce law on divorce rate with US panel data. The reason why these literatures could not have a consensus on the effect of this law on divorce rate is because two-way fixed effects and event study regressions are not robust to heterogeneous treatment effects and in this case, estimates cannot be interpreted as a causal effect. By using alternative estimators to address this issue (e.g. de Chaisemartin and D'Haultfoeuille 2020), I found that divorce rate rose after the adoption of this law and this rise reversed afterwards. Average of dynamic effects is smaller than previous papers found

Join Zoom Meeting: https://ucsb.zoom.us/j/8696371997

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