On financial markets many investment decisions are taken by groups and not by individuals. The evidence, however, whether groups better than individuals, is ambigous. We analyze the portfolios of groups and individuals in an asset allocation task on an experimental market. We find that groups on...

This paper argues that observations of non-stationary choice behavior need notnecessarily imply specific properties of the individual’s discount function. As weshow, the observed “anomalies” in intertemporal choice can alternatively be explained by an individual’s perception of the risk...

We consider a simple CAPM with heterogenous expectations on assets mean returns while keeping the assumption of homogenous expectations on the covariance of returns. Our first result derives the security market line as an aggregation result without using the two-fund-separation property. In...

We consider a dynamic general equilibrium model with incomplete markets in which we derive conditions for separating the savings decision from the asset allocation decision. It is shown that with logarithmic utility functions this separation holds for any heterogeneity of discount factors while...

We explain excess volatility, short-term momentum and long-term reversal of asset prices by a repeated game version of Keynes beauty contest. In every period the players can either place a buy or sell order on the asset market. The actual price movement is determined by average market orders and...

We consider an economy where a finite set of agents can trade on one of two asset markets. Due to endogenous participation the markets may differ in the liquidity they provide. Moreover, traders have idiosyncratic preferences for the markets, e.g. due to differential time preferences for...