Contributions published at Banking (Jean-Charles Rochet)

A number of empirical studies seem to reject the additive separability of preferences that is assumed in most theoretical models of the life cycle. We show that, when additive separability is abandoned and interactions between consumptions at different dates are taken into account, an interesting relation emerges between risk aversion and length of the planning horizon. Specifically, we show that when consumptions at different dates are specific substitutes, risk aversion increases with horizon length. This may explain the surprising empirical finding that individuals seem to increase the share of wealth held in risky assets as they become older. (JEL: D11, D91, G11)

The share of the public sector in health insurance provision varies enormously from country to country. It is larger in more redistributive countries. We provide a possible theoretical explanation for these facts: a public health insurance system, fi nanced by taxes, can be an effi cient means of redistribution, complementary to income taxation. This relies on the assumption of a negative correlation between income and morbidity. We examine the empirical validity of this assumption on macro data.