The November 2 Forbes suggests that health insurance under COBRA provides a clear example of adverse selection in action. COBRA is the law that allows workers who leave a job (either voluntarily or not) to continue participating in the health insurance they were getting from their employer. To do so, however, they have to pay the full monthly premium—both the employee and the employer portions—plus a 2% administrative fee.

That sticker shock means that many eligible individuals decide not to continue their coverage under COBRA. Not surprisingly, those people tend to be healthier than average. The folks who use COBRA, on the other hand, tend to be less healthy—and, therefore, more expensive—than average. As a result, insurance companies report that COBRA coverage is a money loser:

Citi analyst Charles Boorady says health plans lose a considerable amount of money on Cobra policies. He estimates that the loss ratio–the amount spent on care compared to the premium collected–is around 200%.

Earlier this year, the stimulus bill created a federal subsidy that pays up to 65% of COBRA premiums for laid-off workers who meet certain income limits. That boosted COBRA enrollment and, according to the article, worsened the hit on insurers. It will be interesting to see whether the insurance industry raises any objections if Congress considers extending the COBRA subsidy (eligibility currently expires on December 31, 2009).

Bonus: Here's a question I might ask my students in the spring, when we study adverse selection: Would insurers feel differently about a 100% federal subsidy for COBRA coverage for laid-off workers?