The problem of fair pricing of contingent claims is well understood in the contex of an arbitrage free, complete financial market, with perfect information : the so-called arbitrage approach permits to construct a unique valuation operator compatible with observed price rocesses. In the more...

The aim of the paper is to analyze the impact of heterogeneous beliefs in an otherwise standard competitive complete market economy. The construction of a consensus probability belief, as well as a consensus consumer, are shown to be valid modulo an aggregation bias, which takes the form of a...

The problem of fair pricing of contingent claims is well understood in the contex of an arbitrage free, complete financial market, with perfect information: the so-called arbitrage approach permits to construct a unique valuation operator compatible with observed price processes. In the more...

Why do investors keep different opinions even though they learn from their own failures and successes? Why do investors keep different opinions even though they observe each other and learn from their relative failures and successes? We analyze beliefs dynamics when beliefs result from a very...

This paper derives the properties of the discount rate that should be applied to a public-sector project when the affected population has heterogeneous degrees of impatience. We show that, for any distribution of discount rates, the social discount rate has the following properties: it decreases...

Our aim is to analyze the link between optimism and risk aversion in a subjective expected utility setting and to estimate the average level of optimism when weighted by risk tolerance. Its estimation leads to a non-trivial statistical problem. We start from a large lottery survey (1536...

Can investors with irrational beliefs be neglected as long as they are rational on average ? Does unbiased disagreement lead to trades that cancel out with no consequences on prices, as implicitly assumed by the traditional models ? We show in this paper that there is an important impact of...

Can investors with irrational beliefs be neglected as long as they are rational on average ? Do their trades cancel out with no consequences on prices, as implicitly assumed by traditional models? We consider a model with irrational investors, who are rational on average. We obtain waves of...

In this paper we propose a generalization of the comonotonicity notion by introducing and exploring the concept of conditional comonotonicity. We characterize this notion and we show on examples that conditional comonotonicity is the natural extension of the concept of comonotonicity to dynamic...