Risk adjustment in health insurance and its long-term effectiveness.

This paper seeks to create new insights when judging the impact different risk adjustment schemes may have on the incentive to select risks. It distinguishes risk types with high and low profit potential and estimates long-run profits associated with risk selection in four scenarios (no risk adjustment, demographic only, including prior hospitalization, and including prior hospitalization and Pharmaceutical Cost Groups). The database covers 180,000 Swiss individuals over 8 years, 3 of which are used for model building and 5, to estimate insurers' profits due to risk selection in the four scenarios. While these profits prove to be very high without risk adjustment and still substantial with demographic risk adjustment, they become surprisingly low when the crude morbidity indicator 'prior hospitalization' is included in the formula. These results clearly indicate the need for health status-related risk adjustment in insurance markets with community rating, taking into account insurers' planning horizon.