Dissertation Defense: Jihyun Oh
Candidate: Jihyun Oh
Major: Economics
Advisors: James Albrecht, Ph.D. and Susan Vroman, Ph.D.
Essays on Labor Economics
Across three chapters of my dissertation, I explore diverse topics and policy implications related to labor economics. In the first chapter, I investigate the relationship between relative income and deaths of despair in the United States. In the second and third chapters, I analyze South Korea’s dual labor market structure. I study the impact of Korea’s employment protection legislation (EPL) on worker mobility between sectors in chapter 2 and analyze the role of the informal sector in chapter 3.
In the first chapter, I investigate relative income as a possible driver to the increasing deaths of despair among non-Hispanic white male Americans in the United States between 2006 to 2016. I analyze two plausible comparisons in income: non-Hispanic white men’s income relative to that of black and Hispanic men and relative to that of their household members. I find that deaths of despair among younger non-Hispanic white men change more sensitively to relative income compared to the older population.
In the second chapter, I analyze the impact of South Korea’s 2007 EPL on the transition patterns of young male workers between different sectors using a three-state on-the-job search model. While formal workers in South Korea benefit from permanent contracts with better insurance coverage and non-salary compensation, workers with informal status have non-permanent contracts and are mostly not entitled to insurance benefits. In 2007, the Korean government implemented an EPL to prohibit the exploitation of informal contracts. I find that the 2007 EPL benefitted both high-school and college graduate men in the informal sector by facilitating their transition into the formal sector. I also find that starting off in the informal sector has a long-term scarring effect for college graduate men, whereas high-school graduate male workers are not negatively impacted by their entry status in the long run.
In the last chapter, I determine the role of South Korea’s informal sector using a piecewise constant hazard model. Being employed in an informal job may provide workers chances of skill enhancement or may provide employers more information to screen workers into a formal job. Estimated transition patterns suggest that South Korea’s informal sector is a screening device rather than a skill accumulation opportunity for both high-school graduate and college graduate male workers. As most worker transition into the formal sector happens at the beginning of their career without further skill enhancement, this likely supports the dead-end hypothesis of informal jobs.