Vivek Whadwa, director of the Center for Entrepreneurship and Research Commercialization at Duke has written about some interesting research his team has done in the Washington Post.

They found the average age for an entrepreneur is 40 and there are twice as many entrepreneurs over 50 than under 25.

They also found that entrepreneurs with a college degree tend to grow bigger companies than those who dropped out.

But most controversial, Vivek and his team found that the VC industry tends to overstate their role and that most successful companies are not venture backed:

The National Venture Capital Association touts its members’ impact on the U.S. economy, saying they created 12 million jobs and generated $3 trillion in revenue in 2010 (equivalent to 21 percent of the nation’s GDP), and claiming credit for eight out of 10software-industry jobs.

But these numbers do not isolate venture capital’s real role. They include all the revenue generated in 2010 by any company that a venture capitalist ever invested in, at any stage of its existence. Venture capitalists could buy stock in a company before its initial public offering and then claim credit for its success in perpetuity.

Less than 5 percent of venture capital goes to early-stage companies — those taking the risk of developing innovative products. Our analysis of more than 500 companies in high-growth industries revealed that not even 11 percent of these companies took venture capital at any stage of their existence. The Kauffman Foundation ran a similar analysis of companies on the Inc. magazine 500 list and found that only 16 percent of them raised venture capital.

The reality is that venture capital follows innovation. Such investors seek out companies that already have working products and proven business models. Venture capital doesn’t stimulate innovation; it wants in once it looks like a good bet.