Hospitals, managed care, and the charity caseload in California.

We ask whether increasing HMO penetration causes hospitals to cut back on charity care using California hospital discharge data for 1988-1996. There is little evidence at the hospital level that private hospitals respond to HMOs by turning away uninsured and/or Medicaid patients. In the for-profit sector hospitals actually reduce the share of privately insured patients and increase the shares of Medicare patients and Medicaid births. Apparently, HMO penetration reduces the price paid by privately insured patients, making them relatively less attractive to for-profit hospitals.