With the private equity hype machine ratcheting up these days, here is a timely paper analyzing private equity performance. The punchline is that on average private equity has been under performing the S&P 500 by more than an annualized 3%.

Abstract:
This literature review covers the issues faced by private equity fund investors. It shows what has currently been established in the literature and what has yet to be investigated. In particular, it shows the many important questions to be answered by future research. The survey shows that the average investor has obtained poor returns from investments in private equity funds, potentially because of excessive fees. Overall, investors need to gain familiarity with actual risk, past return, and specific features of private equity funds. Increased familiarity will improve the sustainability of this industry that plays such a central role in the economy.