Markowitz versus Michaud: Portfolio Optimization Strategies Reconsidered

Several attempts have been made to reduce the impact of estimation errors on the optimal portfolio composition. On the one hand, improved estimators of the necessary moments have been developed and on the other hand, heuristic methods have been generated to enhance the portfolio performance, for instance the resampled efficiency of Michaud (1998). We compare the out-ofsample performance of traditional Mean-Variance optimization by Markowitz (1952) with Michaud's resampled efficiency in a comprehensive simulation study for a large number of relevant estimators appearing in the literature. In this context we consider different estimation periods as well as unconstrained and constrained portfolio optimization problems. The main finding of our simu-lation study concerning the optimization approach is that Markowitz outperforms Michaud on average. Furthermore, the estimation strategy of Frost/Savarino (1988) proves to work excellent in all analyzed situations

Creative Destruction and Asset Prices

This paper introduces Schumpeter's idea of creative destruction into asset pricing. The key point of our model is that small and value firms are more likely destroyed during technological revolutions, resulting into higher expected returns for these stocks. A two-factor model including market return and patent activity growth - the proxy for creative destruction risk - accounts for a large portion of the cross-sectional variation of size and book-to-market sorted portfolios and prices HML and SMB. The expected return difference between assets with the highest and lowest exposure to creative destruction risk amounts to 8.6 percent annually