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 Incomplete Health Insurance
with Dominique Araya
Status: Draft coming soon
Abstract. This paper studies whether patients sort into health care providers based on expected health gains when access to care entails financial exposure. We develop and implement a marginal treatment effect framework for a binary mortality outcome with both treatment and selection heterogeneity. Using individual-level hospital discharge data from Chile and a continuous instrument based on variations in relative private-public surgery prices, we estimate how the mortality effects of private hospital care vary with patients’ unobserved resistance to seeking private care. We find large mortality reductions for clinically severe patients, but these high-gain patients are often the most reluctant to access private care. This negative sorting is concentrated among low-income patients, suggesting that incomplete insurance undermines allocative efficiency by deterring patients with the largest potential survival gains from using private care.
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, including in the private wings (called ``pensionado") of public hospitals, patients can choose their medical team and receive upgraded accommodation. I estimate event-study and staggered difference-in-differences models separately by insurance status and hospital ownership. PAD adoption increased cesarean section rates among Fonasa patients in public hospitals by 14.5 percentage points. By contrast, PAD adoption in private hospitals had little detectable effect on cesarean rates among Fonasa patients, consistent with the fact that physician choice and private-style delivery arrangements were already part of private care.
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.
