Asserting one's rights to complementary health assistance: the results of a social experiment.

Summary The Aide complémentaire santé (ACS) or "health voucher" was introduced in 2005 to encourage households whose standard of living is just above the CMU-C ceiling to acquire supplementary health coverage through a subsidy. Although the number of beneficiaries has slowly increased since its introduction, the use of the ACS remains low. Two hypotheses can explain this state of affairs: (1) lack of information on the existence of the system, how it works and the steps to take to benefit from it. (2) an insufficient amount of aid, as the complementary health insurance would remain too expensive even after deduction of the aid. In order to test the validity of these two hypotheses, a controlled social experiment was set up by the University of Paris-Dauphine in Lille with a sample of 4,209 insured persons potentially eligible for the ACS. An increased amount of aid and differentiated access to information on the system were offered randomly to certain insured persons. The results show robustly that increasing the amount of the "health check" slightly improves the ACS take-up rate and makes it possible to better target those who are actually eligible. However, the ACS remains a complicated system that has difficulty reaching its target: in total, only 17% of insured persons have applied for the ACS. Only 9% of policyholders invited to attend an information meeting actually did so, and the invitation to the meeting largely discouraged other policyholders, thus cancelling out the effect of the increased cheque. Finally, only 55% of the insured who applied received the aid, the others having been refused the aid because, in most cases, their resources were too high. The difficulty in targeting the eligible population and the resulting significant uncertainty about eligibility are certainly obstacles that add to the complexity of the process.