Precautionary savings and wealth heterogeneity: a reassessment of redistributive and insurance policies.

Summary This thesis is based on the observation that precautionary saving, which results from incomplete insurance markets and a debt constraint (Aiyagari [1994]), is important. This mechanism is therefore likely to modify the impact of economic policies. The thesis project is then to integrate the precautionary savings mechanism into the evaluation of insurance and redistribution policies. The mechanism by which income and inheritance tax progressivities as they exist in France have reduced wealth inequality differs. The progressivity of the income tax reduces the savings of the richest, whereas the progressivity of the inheritance tax creates savings for the bequest motive for the poorest. When agents are able to save, the degressive unemployment benefit can reduce the conflict of objectives between efficiency and equity, unlike Cahuc and Lehmann [2000]. The existence of an aggregate risk that exacerbates individual income risk invites us to reconsider the optimal level of debt significantly upwards.