This note shows that an investor who does not hold positive amounts of all available assets is eventually overtaken by a completely diversified rival investor.

In this paper we analyze the long-run dynamics of the market selection process among simple trading strategies in an incomplete asset market with endogenous prices. We identify a unique surviving financial trading strategy. Investors following this strategy asymptotically gather total market...

We apply perturbation theory to solve the optimal control problem of an investor with time-additive power utility over intermediate consumption and final wealth. Under general conditions we show existence of a power series representation for the prevailing optimal consumption and investment...

We apply perturbation methods to solve in closed form a class of robust control problems, implied by Anderson, Hansen and Sargent setting of a preference for robustness. In the constant investment opportunity set case, we obtain closed form power series solutions for the arising robust Bellman...

We solve analytically the Merton's problem of an investor with time-additive power utility. For general state dynamics, we prove existence of two power series representations of the relevant optimal policies and value functions, which hold for all admissible risk aversion parameters. We...

This paper shows that in financial markets with endogenous asset supply and demand, both rational and noise traders do coexist in the long run. The finding implies that financial markets are neither informationally nor allocationally efficient. While rational traders have a consistently higher...

We argue that the equity premium puzzle stems from a mismatch of applying mental accounting to experiments on risk aversion but not to the standard consumption based asset pricing model. If, as we suggest, one applies mental accounting consistently in both areas the degrees of risk aversions...

o obtain the maximum benefits from diversification, financial theory suggests that investors should invest internationally because of the larger potential for risk reduction. The question that we raise in this paper is how to select the optimal portfolio of countries? This article synthesizes...

We prove that under very weak conditions optimal financial products have to be co-monotone with the inverted state price density. Optimality is meant in the sense of the maximization of an arbitrary preference model, e.g. Expected Utility Theory or Prospect Theory. The proof is based on methods...

We use portfolio theory to quantify the efficiency of state-level sectoral patterns of production in the United States. On the basis of observed growth in sectoral value-added output, we calculate for each state the efficient frontier for investments in the real economy. We study how rapidly...