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...

If profit maximization is the objective of a firm, new information about quality should affect firm behavior only through its effects on market demand. I consider an alternate model in which suppliers are motivated by a desire to perform well in addition to profit. The introduction of quality...

We develop a model of selection that incorporates a key element of recent health reforms: an individual mandate. Using data from Massachusetts, we estimate the parameters of the model. In the individual market for health insurance, we find that premiums and average costs decreased significantly...