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 constructs a general equilibrium model of the interaction between financial intermediaries and financial markets that sheds some light on the short-term volatility of real interest rates. The main findings of the paper are as follows. When financial intermediaries issue contingent...

The theory of asset pricing, which takes its roots in the Arrow-Debreu model, the Black and Scholes formula, has been famalized in a framework by Harrison and Kreps (1979), harrison and Pliska (1979) and Kreps (1981). In these models, securities markets are assumed to be frictionless. The main...

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 ? 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...

This paper presents an equilibrium model in a pure exchange economy when investors have three possible sources of heterogeneity. Investors may differ in their beliefs, in their level of risk aversion and in their time preference rate. We study the impact of investors heterogeneity on the...