Because the Kaufman Foundation is regarded as a VC cheerleader, the May 2012 Kaufman Report is stunning on its appraisal of the industry and its recommendations.
In the past 15 years less than 10 percent of the VC funds have generated any types of returns. In the report, the Kaufman Foundation assesses (1) most general partners as greedy and as refusing to align their interests with those of the Limited Partners (2) large funds of over $1 billion don't return capital, and funds over $500m rarely return capital (3) management fees generate the lions share of a venture capitalist's income, not the carried interest.
What the Report fails to take into account is the impact of Sarbannes Oxley on venture capital returns, instead blaming the returns on larger funds and over allocation (of assets)–which is certainly also true. The stock market has stood still for over 10 years, which somewhat ties to venture returns. It's a contributing "do-loop" (for those of you knowledgable about software programming).