In this Paper we develop a model of intertemporal portfolio choice where an investor accounts explicitly for the possibility of model misspecification. This work is motivated by the difficulty in estimating precisely the probability law for asset returns. Our contribution is to develop a...

In this paper, we show how an investor can incorporate uncertainty about expected returns when choosing a mean-variance optimal portfolio. In contrast to the Bayesian approach to estimation error, where there is only a single prior and the investor is neutral to uncertainty, we consider the case...

In this paper, we show how an investor can incorporate uncertainty about expected returns when choosing a mean-variance optimal portfolio. In contrast to the Bayesian approach to estimation error, where there is only a single prior and the investor is neutral to uncertainty, we consider the case...

We develop a model of portfolio choice to nest the views of Keynes - who advocates concentration in a few familiar assets - and Markowitz - who advocates diversification across assets. We rely on the concepts of ambiguity and ambiguity aversion to formalize the idea of an investor’s...

We develop a model of the gambler's fallacy -- the mistaken belief that random sequences should exhibit systematic reversals. We show that an individual who holds this belief and observes a sequence of signals can exaggerate the magnitude of changes in an underlying state but underestimate their...

We propose a rational theory of momentum and reversal based on delegated portfolio management. A competitive investor can invest through an index fund or an active fund run by a manager with unknown ability. Following a negative cashflow shock to assets held by the active fund, the investor...

We propose a model in which assets with identical cash flows can trade at different prices. Infinitely-lived agents can establish long positions in a search spot market, or short positions by first borrowing an asset in a search repo market. We show that short-sellers can endogenously...

We examine how liquidity and asset prices are affected by the following market imperfections: asymmetric information, participation costs, transaction costs, leverage constraints, non-competitive behavior and search. Our model has three periods: agents are identical in the first, become...

We propose a clientele-based model of the yield curve and optimal maturity structure of government debt. Clienteles are generations of agents at different lifecycle stages in an overlapping-generations economy. An optimal maturity structure exists in the absence of distortionary taxes and...

We study the joint determination of fund managers' contracts and equilibrium asset prices. Because of agency frictions, investors make managers' fees more sensitive to performance and benchmark performance against a market index. This makes managers unwilling to deviate from the index and...