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.

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...

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 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...

The aim of this paper is to explain why cross-sectional estimated migration correlations displayed in the academic and professional literature can be either not consistent, or inefficient, and to discuss alternative approaches. The analysis relies on a model with stochastic migration in which...

In this paper we explain how to use rating histories provided by the internal scoring systems of banks and by rating agencies in order to predict the future risk of a set of borrowers. The method is developed following the steps suggested by the Basle Committee. To introduce both migration...

In this study, we examine whether changes in the investment opportunityset stemming from interest rate and credit risks are priced in the US, theUK and the Swiss equity premia by estimating both two-factor and three-factor versions of Merton’s ICAPM. The systematic pricing of credit riskis...