Premium increases and disenrollment from state risk pools.

State risk pools exist primarily for persons who want to buy health insurance, but are either medically uninsurable or are only able to find a policy at considerably higher cost than the rate for a standard insured person. While some people enroll in state risk pools for extended periods, many enroll only for a limited time. This study analyzes duration of enrollment in eight state risk pools using data from 1988 through 1991. A discrete time hazard model provides estimates of the relationship between voluntary disenrollment and enrollee and plan characteristics. Among other findings, the regressions provide evidence of substantial increases in disenrollment in most states in response to premium increases that either were implemented by the plan or occurred as enrollees aged into higher risk categories.