I'm an Assistant Professor of Economics at the School of Business and Economics of Universidad de los Andes, Chile.
My research focuses on the intersection between industrial organization and health economics.
Email: wxiong@uandes.cl | Link to my CV
Abstract. How does cost sharing affect hospital prices when prices are negotiated? I show that coinsurance can increase negotiated hospital prices by weakening insurers' incentives to bargain. In Chile's managed-competition individual market, negotiated inpatient prices vary widely across insurers within the same hospital and are higher for insurer-hospital pairs with lower expected coverage, especially at high-priced hospitals. A stylized model combining competitive selection with Nash-in-Nash bargaining delivers this prediction when insurer revenues do not fully internalize consumer surplus. Structural demand estimates indicate that inpatient demand is inelastic at the observed coverage, consistent with the insurer exposure channel driving the pattern.
Sorting on Survival Gains under Cost Exposure
with Dominique Araya
Status: Draft coming soon
Abstract. In settings where government-sponsored health care is capacity constrained and access to private providers entails financial exposure, an important question is whether patients sort into private care based on expected health gains. We study this question using a marginal treatment effect (MTE) framework for a binary mortality outcome that allows for both treatment heterogeneity and selection heterogeneity. Using individual-level hospital discharge data from Chile and a continuous instrument based on variation in public voucher subsidy relative to private prices, we estimate how the mortality effects of private hospital care vary with patients’ unobserved resistance to seeking private care. We find negative sorting: cost exposure screens out precisely the patients with the largest expected mortality reductions.
Personalized Childbirth Care and Cesarean Delivery: Evidence from Chile's PAD Program
Summary. Chile has one of the highest cesarean section rates among OECD countries, with especially high rates in the private sector, despite equal reimbursement rates for natural birth and cesarean section. This paper shows that the public-private gap in cesarean delivery is largely attributable to a defining feature of private-style childbirth care: the ability to choose a personalized medical team. The empirical setting is the gradual adoption by Chilean hospitals of Fonasa’s Pago Asociado a un Diagnostico (PAD), a fixed-price bundled payment that allows publicly insured patients to receive childbirth care in participating providers with financial certainty about the final charge. In traditional public hospitals, patients are treated by the medical team on shift. Under PAD, patients can choose their medical team and receive upgraded accommodation. An event-study with staggered difference-in-differences shows that PAD adoption increased cesarean section rates among publicly insured patients in public hospitals by 14.5 percentage points.
The Waiting and Matching Quality Trade-off in Kidney Transplants
Summary. This paper leverages a particular policy in Chile that permits private hospitals that procure deceased donor organs from remote areas to retain one of the two kidneys they receive, prioritizing their own patients. As a result, patients in need of kidney transplantation face different waiting times and matching quality between public and private hospitals: the national list has a longer wait time but better matching quality due to a greater market "thickness" for available kidneys and transplant candidates, whereas the private hospital list has a shorter wait time but lower matching quality. I quantify the tradeoff by comparing the life-years from transplantation between the two sectors, using distance to dialysis centers as an instrumental variable for the binary choice between dialysis and transplantation.
