Index Fundamentalism Revisited

Is there any justification for investing in managed mutual funds, or are managed funds for suckers, as indexing advocates argue? We answer this question by looking at a long time span of real fund returns (27 years) for one specific company (Vanguard) that is notable for its low fees on managed funds. By creating synthetic portfoliosóportfolios based on the assets of Vanguardís mutual fundsówe find that whether index funds or managed funds are the superior buy depends on the time span in question, but that managed funds almost always have a lower standard deviation of return than index funds.