Women make up more than half the workforce in the United States, more than half the college students but only 30 percent of its entrepreneurs.

So what’s up with that?

A recent study by the Kaufman Foundation provides some answers. Simply put, men are more likely to take the plunge with their great ideas than women. Women are less likely to throw caution to the wind when it comes to starting up a businesses. They worry about losing health insurance by leaving traditional jobs behind and they worry about failing.

More than men, the study found that women rely on prior experience and the encouragement of others to believe they can succeed. They rely more on a business partner’s start-up funding. They need role models, such as a family member or another entrepreneur. Mentoring and a support network contribute greatly to their success.

Women more than men feel that experience and a track record is crucial, so much so that it may hold them back.

Interestingly enough, most men and women who start their first business are similarly married, in their early 40s with one child at home. But more women who start their first company are divorced, widowed or single than their male counterparts.

Both men and women rely on personal savings (68 percent of the women, 61 percent of men) for the main funding to start their businesses and they rely on on business partners (29 percent of women, 16 percent men). But men tap into venture, private and angel investors more (42 percent of the men, 32 percent of the women).

But men have their challenges, too. For example, men feel greater pressure to keep a traditional job and be the breadwinner.