Washington Mutual Investors Fund

Our empirical results are based on monthly returns of 1,472 U.S. open-end, domestic equity mutual funds existing at any time between 1975 and 2002. We investigate the performance of the entire cross-section of mutual funds, as well as the cross-section of each of three investment-objective categories, growth, aggressive-growth, and growth and income. We first show that the impact of luck on performance is substantial. Specifically, we find that our estimators of the number of mutual funds with positive or negative performance is much lower than those obtained with the standard approach (only based on significant funds). These differences are informative, since they lead to a completely different assessment of...