Research

Working Papers



This paper studies the extent to which medical care delays affect infant and maternal health, using medical procedure delay orders (MPDOs) issued by more than thirty US states at the beginning of the COVID-19 pandemic and a nationwide large claims dataset. Fuzzy RD estimates suggest that infants born right after MPDOs are more likely to reduce healthcare visits, miss immunizations, and develop health issues related to the perinatal period, particularly within the first four months of life. Moreover, difference-in-difference results show delayed medical care threatens infant health through maternal health. Newborns delivered by women with pregnancy exposure to MPDOs are more likely to be low birth weight, and women are more likely to develop pregnancy-related health problems after MPDOs are in effect.




This paper studies the effect of the permanent closure of office-based physician practices on patient healthcare utilization. First we show that the exit rate of office-based physician practices increased in 2020 using data from a nationwide claims database. Treating this as a supply shock to patients, we then show that permanent physician practice closures increase the probability of visiting hospitals, emergency departments and the cost per service. People from areas associated with greater disadvantage (lower income levels, higher shares of minority population, and Medicaid beneficiaries) as well as the elderly are disproportionately affected.




This paper examines the long-term impacts of the Area Health Education Centers (AHEC) program that promotes medical education and training to local communities. Using an event study strategy, I find the AHEC program expands local health workforce. I then show cohorts with childhood exposure to the AHEC program are less likely to be overweight and have health limitations, report better subjective health, are less depressed, and consume fewer alcohol drinks and cigarettes during adulthood than those without any childhood exposure to the local AHEC. Furthermore, these cohorts are more likely to remain enrolled in school after 16 and pursue a higher education degree. The long-term effects of childhood exposure to the AHEC program are larger among minority population and people with less-educated parents.




This paper investigates the impacts of early-life exposure to persecution on human capital formation and marital sorting and analyzes how such impacts depend on the timing of the exposure over early life. By utilizing the ``class struggle" period of China in the form of persecuting landlords, capitalists, intellectuals, etc., I show that persecution survivors with longer early childhood exposure to mistreatment complete less formal schooling, have worse cognitive skills, and earn lower incomes in the long run. Furthermore, they are more likely to marry people from classes once favored by the regime but with poorer human capital outcomes.




Interdisciplinary research is commonly celebrated and encouraged for its ability to address emergent problems but little is known about the people who conduct such work since career-level data has not been broadly accessible. Extant theoretical frameworks generate competing predictions that (a) interdisciplinarians will be rewarded for brokering disparate areas of knowledge or (b) interdisciplinarians will be penalized for deviating from a single disciplinary category or prototype. We draw upon two large datasets covering more than one million dissertations from 1986 through 2016 from the United States as well as a novel linkage of the data and show that (1) interdisciplinary dissertations have become consistently more common and (2) working as an interdisciplinary dissertator tends to be penalized (based on recent years of salary data). More specifically, we find that the distance of topics that are combined in interdisciplinary dissertations is variably important across fields; and, when fields offer relatively high pay (e.g., Business), the penalty appears to be steeper. Our findings suggest a potential conflict of interest between enterprise-level interests to support interdisciplinary research and individual-level experiences of doing interdisciplinary work. Our study contributes to theories regarding the experience of interdisciplinarians across a wide range of organizational environments.




Marketing and strategy researchers have often studied how organizations navigate multiple identities in relation to category spanning but extant literature pays less attention to understanding how individuals do so. Moreover, current econometric approaches only scratch the surface with respect to addressing the impact of multiple identities in professional settings. As a model domain to study labor market returns when individuals have more than one identity, we focus on interdisciplinary dissertators in the United States since evidence shows clear uptrends in dissertators engaging multiple professional identities and unclear trends in their outcomes. Our novel estimation method leverages a two-step process to characterize salaries of interdisciplinary dissertators as functions of the identities (academic fields) they acquire as graduate students. We estimate a first-stage regression of log earnings for monodisciplinarians on field dummies and respondent characteristics. After capturing the estimated field coefficients, we then regress log earnings for interdisciplinarians on linear and non-linear functions of these coefficients. Our estimates robustly reject the hypothesis that interdisciplinarians receive a salary premium. We also find evidence that the academic market, but not other employment sectors, particularly compensates researchers based on their primary discipline, an outcome that challenges emphases on interdisciplinarity. While our findings for interdisciplinarians point to the primary identity holding predominant importance for doctoral graduates in the United States, our two-step method provides a framework for parsing and estimating the varied impacts of multiple identities across a wide range of contexts.




The novelty of this paper is to comparatively study the intergenerational economic mobility in rural and urban China through an exploration of multiple intergenerational transmission mechanisms. Comparing rural and urban households in China, this paper finds lower intergenerational economic mobility in urban areas over the past quarter century (1989 to 2015). Furthermore, using the predicted community average parental human capital and nonhuman capital measures as instruments, the 2SLS estimates show that parental human capital has a bigger impact on child income in rural than urban China, while parental nonhuman capital goods, such as household wealth and social spending, are relatively stronger intergenerational economic transmission mechanisms within the urban households than the rural ones. This paper casts light on the heterogeneous intergenerational economic transmission patterns in China's dual society under the Rural-Urban Household Registration System. Moreover, the existing rural-urban difference of intergenerational economic transmission does not diminish with internal labor migration.




The United States rose to become a global leader in scientific research in the early 20th Century. Using comprehensive data matching the universe of ProQuest PhD recipients to the full count decennial US Censuses (1850-1940), this paper investigates how access to PhD training facilitated research manpower in the US during this critical period. Evidence from our event study design suggests that opening one more PhD program during the peak ages of graduate study induces about 2 more PhD recipients per 1 million people born in that state. Furthermore, the expansion of PhD programs improved access for minority, immigrant, and lower socioeconomic status families. We also find that the location and field of the PhD program openings help to determine the institution and research area of doctoral recipients.



  • Robots, Demand for Skill and Inequality: Evidence from the China Employer-Employee Survey (with Albert Park and Xiaobo Qu)


This paper examines the equilibrium effects of the most recent automation technology transition towards industrial robots in the manufacturing industry using the newly collected China Employer-Employee Survey (CEES) data. We correct the endogeneity issue by using the constructed provincial capture of nationwide robotics technology as the instrumental variable for the individual firm's use of industrial robots. The 2SLS estimates show that the use of industrial robots in manufacturing firms awards wage premiums to all types of jobs and workers, meanwhile, also reshapes the employment structure and augments wage inequality within the firm. Moreover, the heterogeneity analysis across education groups, occupation levels, and task contents suggests that the shift in the demand for skill is the mechanism, through which the industrial robots affect the labor market.




We study how human capital diversification, in the form of double majoring, affects how earnings respond to labor market shocks. Multiple data sets show that double majors are substantially buffered against earning shocks, especially when the two majors are very different. This insurance effect is stronger among underrepresented groups, including women and minorities. Our exploration of mechanisms shows that double majors make different occupation choices than similar single majors. They also enter occupations demanding more high-level skills and knowledge, suggesting that they have a wider range of skills and knowledge.


Work In Progress


  • Short-term and Long-term Impacts of Childhood Exposure to Racial Injustice



  • Out of the University, Into the Workforce: Early 20th Century Scientific Training and Industrial Research (with Peter Nencka)


  • Short-term and Long-term Impacts of Opening Medical Schools (with Rebecca McKibbin and Ioanni Nicholopoulos)