"Despite all the evidence to the contrary, suppose an investor still believed that superior investment management really does exist. Two issues remain: First, it is clear that such skill is very rare; and second, there appears to be no effective way to find such skill before it has been demonstrated. As I indicated in chapter 7, the best-performing funds in one period of time are not the best performers in the next period. The top performers of the 1990s had dreadful returns in the first decade of the 2000s. Paul Samuelson summed up the difficulty in the following parable. Suppose it was demonstrated that one out of twenty alcoholics could learn to become a moderate social drinker. The experienced clinician would answer, "Even if true, act as if it were false, for you will never identify that one in twenty, and in the attempt five in twenty will be ruined." Samuelson concluded that investors should forsake the search for such tiny needles in huge haystacks."