From 1991 to 2003, the fraction of Medicaid recipients enrolled in HMOs and other forms of Medicaid managed care (MMC) increased from 11 percent to 58 percent. This increase was largely driven by state and local mandates that required most Medicaid recipients to enroll in an MMC plan....

The hospital market is served by firms that are private for-profit, private not-for-profit, and government-owned and operated. I use a plausibly exogenous change in hospital financing that was intended to improve medical care for the poor to test three theories of organizational behavior. My...

State governments contract with health maintenance organizations (HMOs) to coordinate medical care for nearly 20 million Medicaid recipients. Identifying the causal effect of HMO enrollment on government spending and health care quality is difficult if, as is often the case, recipients have the...