Effect of complementary health insurance on medical consumption, between moral hazard and improved access to care.

Summary Economic theory leads one to assume that health insurance increases medical consumption by generating ex-post moral hazard, i.e. the purchase by individuals of care whose value is low in relation to its total cost. Some economists point out that all or part of this consumption surplus may also result from the solvency of the demand for care as a result of reimbursements, thus reflecting better access to care. Understanding which of these effects predominates is an important issue in terms of equity and efficiency of the health care system. This thesis aims to measure the magnitude of the effect of supplementary health insurance on medical consumption in France and to understand its nature by drawing on three articles. The first article analyses the effect of being covered by a complementary health insurance on the use of doctors, the second evaluates the impact of the CMU-C on the medical consumption of its beneficiaries, and finally the third studies the effect of a supplementary health insurance allowing to complete the reimbursements of the basic contract of a civil servant mutual insurance company. By focusing on complementary and supplementary insurance, these articles allow us to study the effect of a marginal variation in the level of coverage on different categories of the population.