The impact of health plan report cards on managed care enrollment.

How does the release of health plan performance ratings influence employee health plan choice? A natural experiment at General Motors (GM) Corporation provides valuable evidence on this question. During the 1997 open enrollment period, GM disseminated a health plan report card for the first time. By comparing 1996 and 1997 enrollment patterns, our analysis estimates the impact of the report card information while accounting for fixed, unobserved plan traits. Results indicate that employees are less likely to enroll in plans requiring relatively high out-of-pocket contributions. Results with respect to report card ratings suggest that individuals avoid health plans with many below average ratings.