I am an assistant professor in the Graduate School of Economics at the University of Osaka in Japan.
My research interests center on health economics, with a particular focus on the health and well-being of families and children.
contact: chien-tzu_cheng(at)econ.osaka-u.ac.jp
See You at Night: Unintended Consequences of Raising Provider Payments for Nighttime Emergency Care
with Hsien-Ming Lien [Draft]
Using administrative data from Taiwan’s single-payer healthcare system, this paper studies a 2010 reform that increased nighttime payments to emergency department (ED) physicians by 25 percent. Exploiting the resulting payment discontinuity, we employ a regression discontinuity in time (RDiT) design and adopt an augmented local linear approach to address identification challenges inherent to time-based running variables. We find no effects on overall care provision or visit volume. Instead, we document a 33 percent increase in the share of low-acuity visits during nighttime hours, with no corresponding change among high-severity cases, consistent with hospitals strategically re-timing low-acuity patients to increase reimbursement. Using daytime visits as a within-hospital control in an event-study framework, we find little impact on hospitalization, length of stay, costs, or mortality up to one year after implementation. The results suggest no evidence of substitution between emergency and primary care, indicating that the observed responses reflect supply-side behavior rather than patient demand.
When More Prenatal Care Looks Like Less: Evidence on Selection and Detection from the SARS Epidemic
with Shin-Yi Chou, Hsien-Ming Lien [Draft available upon request.]
We use the 2003 SARS epidemic in Taiwan as a natural experiment, instrumenting prenatal care with gestational exposure to SARS-induced fear that reduced visits by more than 20 percent. Adequate prenatal care reduces preventable maternal complications by 3.4 percentage points (26 percent), with no detectable effect on infant outcomes. OLS estimates are perversely signed for maternal complications, suggesting more care worsens outcomes, while overstating benefits for infant outcomes, a divergence consistent with the detectability of risk during pregnancy. Prenatal care functions as a diagnostic system: disrupted monitoring suppressed detection of asymptomatic conditions and reduced appropriate cesarean-section routing.
The Impact of Home Pregnancy Testing on Fertility and Women's Later-Life Outcomes
[Draft available upon request.]
Home pregnancy tests give early fertility information and help women make timely family-planning decisions. This paper studies how the introduction of home pregnancy tests in the US in 1977 impacted fertility, early prenatal care, and later-life outcomes. Using county-level drugstore accessibility to approximate test availability, I document significant trend breaks in fertility rates after 1977 among women who had access to drugstores. The effects are the strongest for those aged 15–29 and concentrated among those with access to abortion services. In the long run, women exposed to home pregnancy tests were more likely to delay childbirth, participate in the labor force, and never marry; these women were also less likely to divorce.