Soohyung Lee

IEA – Could you walk us through the key moments that shaped your path – from your earliest exposure to economic thinking, to what sparked your interest in the field, and ultimately what drew you to academic research?

Soohyung – I was first exposed to economics during my first year of high school. Although the textbook content at that time was limited, I was fascinated by the systematic way it examined society through economic activity and individual decision-making. This initial interest led me to major in economics at Seoul National University. My experience studying economics as an undergraduate far exceeded my expectations, and I still feel very fortunate to have chosen this field.

While in college, I wrestled with the decision between taking the civil service exam to become an elite policymaker or pursuing further academic study. At that time, my undergraduate advisor, Dr. Tae Sung KIM, encouraged me to do both. He told me that South Korea needed well-trained government officials and advised me to build a strong foundation in economics while preparing for the civil service exam so that I would be able to gain admission to top PhD programs in the US after gaining government experience.

I took his advice, and after serving four years at South Korea’s Ministry of Finance (MOF), I enrolled in the PhD program in economics at Stanford University. It was somewhat unconventional for a government official to leave for graduate school so early as most wait to receive a government fellowship, which usually takes over a decade of service. I decided to apply for a graduate program much earlier than the norm because, by that point, I felt I had gained enough experience at the MOF and wanted to upgrade my skills through world-class academic training at Stanford, with the goal of applying that knowledge to policymaking.

However, my journey did not unfold as I had initially planned. The Korean government granted me only five years of leave to complete my graduate studies, but it took six years to finish my PhD at Stanford. As a result, I had to resign from my position at the MOF while still in the program. Like many other economics PhD candidates, I went through the standard job search process and ultimately secured a faculty position at the University of Maryland, College Park, thus starting my academic career.

Although I transitioned from policymaker to academic researcher, I find my work is often complementary to policymaking because I choose research topics relevant to real-world issues. Moreover, the academic setting allows me more time and freedom than policymakers typically have to study these issues with academic rigor.

IEA – In your study on long commutes in South Korea, you found significant health implications. Could you walk us through how you addressed potential endogeneity concerns when linking commute duration to health outcomes? What surprised you most about your findings?

Soohyung – That research question was motivated by my own experience as a government official in South Korea. I observed that many policy decisions in Korea were made without sufficient scientific assessment. One that stands out was the decision to relocate most government agencies and other public sector employers to the middle of the country, creating a new administrative capital later named Sejong City. My colleagues who started their careers around the same time as I did in various ministries had to bear the direct consequences of that policy. Many of them either commute daily from Seoul to Sejong, which takes about four hours round trip, or live apart from their families during the workweek. Many complain about back and muscle pain, lack of sleep, and difficulty maintaining a work-life balance.

There is a growing body of health research reporting the negative effects of long commutes in several countries. As a former government official, I felt a personal responsibility to assess the extent to which such a work arrangement might affect people’s health in the South Korean context. For causal inference, my co-author, Seulgi Lim, and I calculated the proportion of public sector workers residing in each location immediately before Sejong City was established. We then used the geographical variation in these proportions as an instrument for the share of long-distance commuters among workers.

Our empirical results were surprising in two ways. First, the magnitude of the impact on health outcomes and healthcare costs was much larger than I had expected. In a given year, a one percent increase in the share of long commuters—defined as those commuting at least two hours per day—led to a 3.5 percent increase in the number of workers visiting a hospital at least once, a 4.0 percent rise in the total number of hospital visits, a 5.3 percent increase in worker copayments, and a 9.1 percent increase in medical expenses paid by the National Health Insurance System. Second, I was struck by how people adjusted their health-related behaviors. In our sample, longer commutes were associated with reductions in both harmful activities (like smoking) and beneficial activities (like exercising). This finding may simply reflect the fact that people who spend more time commuting have less time for leisure and other activities. Still, I find it interesting that a hardship—namely, a longer commute—can bring about positive behavioral changes, even if those changes are small.