Should Top Surgeons Practice at Top Hospitals? Sorting and Complementarities in Healthcare
How do physician sorting across hospitals and physician-hospital complementarities influence aggregate patient outcomes? I estimate the joint production function of patient survival between surgeons and hospitals in the context of coronary artery bypass graft (CABG) surgery using a two-step grouped fixed effects approach with partial endogenization of network formation. I find that cardiac surgeons engage in positive assortative matching, where high-survival surgeons tend to practice at high-survival hospitals. At the same time, surgeon and hospital value-added are substitutes, such that low-survival surgeons exhibit higher returns from practicing at a high-survival hospital than high-survival surgeons do. I use my estimates to examine the impact of provider sorting across and within regions on aggregate survival. Surgeon sorting across hospitals has large consequences for aggregate patient outcomes. Substantial mortality gains could be achieved by reallocating surgeons within their regions, though such reallocations would exacerbate differences across regions.
Market Size and Trade in Medical Services
Revisions requested at American Economic Review
NBER WP #31030 (with Jonathan Dingel, Josh Gottlieb, and Maya Lozinski)
We uncover substantial interregional trade in medical services and investigate whether regional increasing returns explain it. In Medicare data, one-fifth of production involves a doctor treating a patient from another region. Larger regions produce greater quantity, quality, and variety of medical services, which they “export” to patients from elsewhere, especially smaller regions. We show that these patterns reflect scale economies: greater demand enables larger regions to improve quality, so they attract patients from elsewhere. Despite concerns about rural access, larger regions have higher marginal returns to spending. We study counterfactual policies that would lower travel costs rather than relocating production.
Media mention: Washington Post, The Center Square
Firms, Markets, and the Division of Labor: The Case of Physicians
Why and how do physicians co-locate to provide care? We establish several novel facts regarding this question. First, the number of healthcare organizations grows with an elasticity near one with market size, so that a doubling of population results in twice as many healthcare organizations. Notably, the average size of healthcare organizations does not increase measurably with the market size. We also show that the composition of organizations varies substantially with market size, even though they remain the same size. As market size grows, physicians co-locate more with same-specialty colleagues, individually produce a narrower set of services, and collectively produce a larger set and volume of services. These results suggest that coordination costs substantially constrain organization size. In addition, they imply that same-specialty colleagues become more valuable as the market size grows due to an increasingly fine division of labor, allowing for production efficiencies.