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. This paper studies how selection outcomes in an individual insurance market shape the hospital market. In a setting with horizontally and vertically differentiated hospitals, consumers who prefer high-quality but expensive 'star' hospitals are costlier to insure. Competitive multi-plan insurers respond by offering tiered- and narrow-network plans to attract consumers less likely to use expensive providers. However, enrollment in these plans reduces the average coverage that insurers assume at star hospitals and weakens insurers' bargaining incentives, creating a feedback loop that elevates star hospital prices and enlarges the premium differences between network policies. Using industry-wide claims and enrollment data from Chile, I estimate that insurers' tiered provider networks explain 18% of the observed three-fold price ratio between high- and low-cost hospitals. Eliminating network choices mitigates both adverse and advantageous selection on hospital preferences, shifts patients toward star hospitals, and reduces profitability disparities across providers.
Save Lives with Private Care: Provider Choice and Voucher Design in Healthcare (with Dominique Araya)
Status: Draft coming soon
Abstract. This paper examines the mortality benefit of hospital choice while accounting for patient self-selection. Using ten years of nationwide hospital discharge data from Chile, we show that allocating urgent patients to providers with fewer capacity constraints significantly improves survival outcomes. However, patients who stand to benefit most from the more responsive capacity in private hospitals are also less likely to select private care, largely due to incomplete insurance coverage exposes severe patients to the financial risk of paying for care. We provide two sets of empirical evidence. First, we study a subsample of patients reallocated by a centralized, capacity-based transfer system both prior to and during the COVID-19 pandemic, offering quasi-random exposure to hospital type. Second, we estimate the survival gain from private care using a control function approach that addresses self-selection by exploiting exogenous choice shifters. Building on the estimated survival gains and observed selection patterns, our counterfactual analysis proposes an alternative voucher design that promotes positive Roy selection and improves survival.
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.
Pricing Water under Scarcity and Adverse Selection: Theory and Evidence (with Juan-Pablo Montero)
Summary. We confirm an emerging empirical observation that utility consumers respond to average price rather than marginal price. Given the average price bias, we derive optimal block price schedules under water scarcity. We estimate the key parameters using detailed administrative data that spans ten years and covers every household in the Metropolitan region of Santiago, Chile.
