Women own about 36 percent of all U.S. companies, but when it comes to fast-growth entrepreneurship, women are relatively scarce. Only 10 percent of the Inc. 500, an annual ranking of the fastest-growing private companies in the U.S., are led by women; women CEOs get only three percent of venture capital.

The causes of this disparity can be as varied as the people trying to figure it out. But in Silicon Valley, center of both the technology and venture capital industry, one explanation looms large: "We clearly have a pipeline problem," says Beth Seidenberg, a general partner at Kleiner Perkins Caufield & Byers. By "pipeline," Seidenberg means that very few women earn the types of undergraduate degrees that venture capitalists typically look for. Seidenberg herself specializes in digital health and biotech, home to a number of notable women-led companies: Theranos, 23andMe, and Care.com, for starters.

But computer science and information technology are the biggest offenders: Women earn just 18 percent of undergraduate degrees in computer science, and 19 percent of engineering degrees. Worse, the numbers in computer science have been shrinking for 10 years: In 2004, women earned 23 percent of computer science degrees.

Eighteen percent is a hard number to argue with. How can women be expected to get half of venture capital, in an industry dominated by tech, if they don't have anywhere near half the coding skills?

Yet as venture capitalists start to back more consumer companies, it's increasingly appearing that just maybe, the pipeline isn't as all-important as it's been thought to be. Blue Bottle Coffee, after all, has raised $116 million in venture capital; its (male) founder was formerly a freelance musician.

Plus, the "pipeline" explanation raises almost as many questions as it raises: If the number of women earning computer science degrees is the lowest it's been in 10 years, why do venture capitalists agree that the number of women with the requisite skills to build and fund a company has only increased in that time? Why has the percentage of venture capital that goes to a company with a woman on the founding team actually been increasing, from five percent in 1999 to 18 percent in 2013? And how is it that a recent report from First Round Capital, which evaluated about 300 investments and 600 co-founders, found that, with the exception of enterprise technology companies, having a technical co-founder actually hurts a startup's performance--by 31 percent?

"The pipeline is somewhat of a problem," says Theresia Gouw, founding partner of venture capital firm Aspect Partners. "It's also a convenient excuse."

Getting Schooled

There's no question that degrees matter. In some fields, they matter more than others. Women entrepreneurs seem to have made a lot more headway in health care, for example, than in technology. Not coincidentally, the number of women who earn MDs is almost the same as the number of men--women earn about 48 percent of MDs—and that number has been above 40 percent for about two decades. So you can see why VCs such as Seidenberg put a heavy emphasis on the pipeline. They don't think it's the only problem, of course, but they've seen women achieve something close to educational parity in medicine, and eventually, bring that expertise to the startup world. So maybe it's the same problem in software.

"I think it's true that there's less of a pipeline problem in the life sciences," says Terry McGuire, founding partner of VC firm Polaris Partners. "If you look at the training, I see as many women PhDs and women MDs as men. And if you look at the people who come through big pharma, there are growing ranks of women there too. In that sense the pool is just getting richer and deeper and bigger."

Here it's worth remembering that computer science is not health care, and that plenty of male entrepreneurs who have succeeded with software or tech companies--Mark Zuckerberg and Steve Jobs being two of the best-known--don't have computer science degrees either. "When we talk about CEOs of billion-dollar companies, all the male CEOs don't necessarily have engineering degrees or computer science degrees or even backgrounds in those fields," says Gouw. That holds true for the women, too. Both Meg Whitman and Sheryl Sandberg, for example, were economics majors as undergrads, then got their MBAs.

Coding may not be as all-important as it once was, either, even for those building companies with a big software or technology component. Gouw points out that there's still a lot of work to be done to capitalize on even the better-known advances in science and technology. She thinks we're going to see more businesses "really built on business model change," or on the creative application and customization of technology to new market opportunities. The ability to suss out those applications and markets, Gouw says, "is available to founders and CEOs with more diverse skill sets, including women."

That suggests that while a company may still need high-level tech skills, it doesn't need to be the founder or co-founder who's doing the engineering. "I'm not looking for a technical CEO," says Jessica Herrin, an angel investor and founder and CEO of Stella & Dot, which sells jewelry and other products for women via a web-enabled direct sales model. "But on the core team, I'm 100 percent looking for a technical person. If a team is looking to outsource development, I don't think any investor looks at that as desirable."

Sheila Lirio Marcelo, the co-founder and CEO of Care.com, a marketplace for caregivers and those who hire them, says she'd rather see a founder who is a product management pro, as opposed to a hard-core engineer or coder. "Product people talk the language of technologists, but they don't have to code. They have enough understanding of how a product is built to have a dialog with marketing and with engineering to realize monetization," she says.

Amy Millman, the co-founder and president of Springboard Enterprises, which mentors women entrepreneurs and helps them get venture backing, says all the emphasis on technical skills is in part a holdover from the early days of Silicon Valley. "We've gone through 30 years of focusing on routers and switches," she says. "Now that we've built all of that, now we can actually sell stuff. That's where women play."

Millman says that whether or not an entrepreneur can code should absolutely not make a difference. "You don't need to know how to code," she says. "You just need to know somebody who does. If you can't pull together the team to be successful, you're not going to be a CEO."