Theory of social insurance in a multirisk universe.

Summary The standard theory of insurance demand, based on risk aversion on the part of the insured, predicts full insurance under actuarial premiums or partial insurance, i.e. full insurance beyond the deductible, in the presence of proportional loading (arrow, 1965). Faced with the various paradoxes that have come to light since that date, an alternative, innovative approach, based on the insurance application of the multi-risk market concept, developed in the early 1980s (doherty et al. In the face of the various paradoxes that have been uncovered since then, an alternative, innovative approach, based on the insurance application of the multi-risk market concept, was developed in the early 1980s (doherty and schlesinger (1983, 1985), eeckhoudt, gollier, schlesinger (1991), villeneuve and koehl (1996). . ). It allows to extend the spectrum of market solutions by taking into account the multiplicity of risks incurred by the insured. Our work uses these new theoretical developments to better understand social insurance systems. In the presence of anti-selection among insureds, linked contracts emerge: they allow us to illustrate the financing transfers at work in social protection. Moreover, compulsory markets appear to have different impacts on the demand for voluntary insurance by individuals, depending on their membership of a risk category and on the correlations in force between the sources of risk. Moreover, when policyholders differ only in their initial wealth, we draw all the consequences, in the complementary markets, of four types of redistribution at work in the compulsory markets: redistribution in price and quantity on the one hand, redistribution between policyholders and between periods on the other, by introducing temporal preferences as a characteristic of policyholders.