"We evaluate the academic research on mutual fund performance in the US and UK concentrating particularly on
the literature published over the last 20 years where innovation and data advances have been most marked. The
evidence suggests that ex-post, there are around 2-5% of top performing UK and US equity mutual funds which
genuinely outperform their benchmarks whereas around 20-40% of funds have genuinely poor...."
Nitzsche, Dirk and Cuthbertson, Keith and O'Sullivan, Niall, Mutual Fund Performance (2006)
Source: http://ssrn.com/abstract=955807
