When investors have incomplete information, expected returns, as measured by an econometrician, deviate from those predicted by standard asset pricing models by including a term that is the product of the stock’s idiosyncratic volatility and the investors’ aggregated forecast errors. If...

We consider a pure exchange economy with incomplete information. Some agents display learning bias and over- or under-react to the arrival of new information. We show under which conditions biased agents survive over a finite horizon. We also study the distribution of irrational agents...

We consider a pure exchange economy where the drift of aggregate consumption is unobservable. Agents with heterogeneous beliefs and preferences act competitively on financial and goods markets. We discuss how equilibrium market prices of risk differ across agents, and in particular we discuss...

This paper studies equilibrium in a pure exchange economy with unobservable Markov switching consumption growth regimes and regime-dependent preferences. Variations in risk attitudes have fundamental effects on the structure of equilibrium. Explicit solutions are provided for the market price of...

We construct mean-variance portfolios using a factor model approach. We show the importance of portfolio allocation for large unbalanced equity data sets using the full CRSP database. We compare the performance of our portfolio construction methodology to the 1/N naive diversification strategy,...