NBER Publications by Jonathan T. Kolstad

We implement an empirical test for selection into health insurance using changes in coverage induced by the introduction of mandated health insurance in Massachusetts. Our test examines changes in the cost of the newly insured relative to those who were insured prior to the reform. We find that counties with larger increases in insurance coverage over the reform period face the smallest increase in average hospital costs for the insured population, consistent with adverse selection into insurance before the reform. Additional results, incorporating cross-state variation and data on health measures, provide further evidence for adverse selection.

In April 2006, the state of Massachusetts passed legislation aimed at achieving near universal health insurance coverage. A key provision of this legislation, and of the national legislation passed in March 2010, is an individual mandate to obtain health insurance. Although previous researchers have studied the impact of expansions in health insurance coverage among the indigent, children, and the elderly, the Massachusetts reform gives us a novel opportunity to examine the impact of expansion to near-universal health insurance coverage among the entire state population. In this paper, we are the first to use hospital data to examine the impact of this legislation on insurance coverage, utilization patterns, and patient outcomes in Massachusetts. We use a difference-in-difference strategy ...

Prior studies suggest that, with elastically supplied inputs, free entry may lead to an inefficiently high number of firms in equilibrium. Under input scarcity, however, the welfare loss from free entry is reduced. Further, free entry may increase use of high-quality inputs, as oligopolistic firms underuse these inputs when entry is constrained. We assess these predictions by examining how the 1996 repeal of certificate-of-need (CON) legislation in Pennsylvania affected the market for cardiac surgery in the state. We show that entry led to a redistribution of surgeries to higher-quality surgeons and that this entry was approximately welfare neutral.