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.
Survival and Selection under Incomplete Insurance: Evidence from Chile’s Mixed Public-Private Health System
with Dominique Araya
Status: Draft coming soon
Abstract. This paper investigates the mortality effects of private hospital use among government-insured patients. We develop and estimate a marginal treatment effect framework for a binary outcome that allows for both selection heterogeneity and treatment effect heterogeneity. Using eight years of nationwide hospital discharge data from Chile and a continuous instrumental variable derived from variation in public voucher subsidies, we find large heterogeneity in treatment effects: for some patients, private hospital admission increases survival probabilities by up to 10-15 percentage points. Patient self-selection is shaped by two opposing forces: while Roy sorting drives patients with high potential survival gains toward private hospitals, financial risk deters them from doing so. Because private hospitals hold a capacity advantage in intensive care, comparing self-selection with centralized transfers highlights the potential of relaxing financial barriers to enable positive Roy sorting to realize the survival advantage 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.
