Governments often contract with private firms to provide public services such as health care and education. To decrease firms' incentives to selectively enroll low-cost individuals, governments frequently "risk-adjust" payments to firms based on enrollees' characteristics. We model how risk...

This expository paper describes the factors that contribute to failure of health insurance markets, and the regulatory mechanisms that have been and can be used to combat these failures. Standardized contracts and creditable coverage mandates are discussed, along with premium support, enrollment...