PERON Mathilde

This thesis deals with two questions relative to efficiency and fairness in mixed health insurance systems with partial mandatory coverage and voluntary supplementary health insurance (SHI): (i) the inflationary effect of SHI on medical prices. (ii) the fairness of SHI premiums. We set the analysis in the French context and perform empirical analyses on original individual-level data, collected from the administrative claims of a French insurer (MGEN). The sample is made of 99,878 individuals observed from 2010 to 2012. In Chapter 1, we estimate the causal impact of a generous SHI on patients' decisions to consult physicians who balance bill their patients. We find evidence that better coverage contributes to the rise in medical prices. In Chapter 2, we specify individual heterogeneity in moral hazard and consider its possible correlation with coverage choices. We find evidence of selection on moral hazard: individuals who are more likely to ask for coverage exhibit stronger moral hazard. In Chapter 3, results show that when SHI is voluntary, age-based premiums maximize transfers between low and high healthcare users but do not guarantee vertical equity.

This thesis is devoted to mixed health insurance systems where compulsory public coverage can be improved by a complementary health insurance. The questions addressed concern the inflationary effect of the complementary health insurance on the price of care and the impact of age-based pricing on solidarity between sick and healthy people and between income groups. The empirical analyses are based on French data. This original database includes the health care consumption of 99,878 MGEN members over the 2010-2012 period. Chapter 1 estimates the causal effect of better coverage on the consumption of excess fees and demonstrates the inflationary effect of complementary health insurance on the price of care. Chapter 2 considers the heterogeneity of the impact of better coverage on overcharges and its correlation with insurance demand. In fact, the inflationary effect of complementary insurance is accentuated by selection effects. Chapter 3 shows that age-based pricing maximizes transfers between the sick and the healthy at the expense of solidarity between high and low incomes.

We evaluate the causal impact of an improvement in insurance coverage on patients’ decisions to consult physicians whocharge more than the regulated fee. We use a French panel data set of 43,111 individuals observed from 2010 to 2012. Atthe beginning of the period, none of them were covered for balance billing. by the end, 3819 had switched to supplementaryinsurance contracts that cover balance billing. Using instrumental variables to deal with possible non-exogeneity of thedecision to switch, we find evidence that better coverage increases demand for specialists who charge high fees, therebycontributing to the rise in medical prices. People whose coverage improves increased their average amount of balancebilling per consultation by 32%. However, the impact of the coverage shock depends on the supply of physicians. Forpeople residing in areas where few specialists charge the regulated fee, better coverage increases not only prices but alsothe number of consultations, a finding that suggests that balance billing might limit access to care. Conversely, in areaswhere patients have a genuine choice between specialists who balance bill and those who do not, we find no evidence of aresponse to better coverage. Copyright © 2016 John Wiley & Sons, Ltd.

In this paper, we estimate the causal impact of a positive shock on supplementary health insurance coverage on the use of specialists who balance bill. For that purpose, we evaluate the impact on patients' behavior of a shock consisting of better coverage of balance billing, while controlling for supply side drivers, i.e. proportions of physicians who balance bill and physicians who do not. We use a panel dataset of 58,336 individuals observed between January 2010 and December 2012, which provides information, at the individual level, on health care claims and reimbursements provided by basic and supplementary insurance. Our data makes it possible to observe enrollees that are heterogeneous in their propensity to use physicians who balance bill. We observe them when they are all covered by the same supplementary insurer, with no coverage for balance billing, and after 5,134 of them switched to other supplementary insurers which offer better coverage. Our estimations show that better coverage contributes to a rise in medical prices by increasing the demand for specialists who balance bill. On the whole sample, we find that better coverage leads individuals to raise their proportion of consultations of specialists who balance bill by 9 %, which results in a 34 % increase in the amount of balance billing per consultation. However, the effect of supplementary health insurance clearly depends on the local supply side organization. The inflationary impact arises when specialists who balance bill are numerous and specialists who do not are relatively scarce. When people have a real choice between physicians, a coverage shock has no impact on the use of specialists who balance bill. When the number of specialists who charge the regulated fee is sufficiently high, there is no evidence of limits in access to health care, nor of an inflationary effect of supplementary coverage.