He claims that the difference between men's and women's interest in tech startups is not skewed enough to explain the skewed male/female ratio in the tech star

He claims that the difference between men's and women's interest in tech startups is not skewed enough to explain the skewed male/female ratio in the tech startup world. ("...all of the research I am aware of suggests that these differences are extremely small – not nearly big enough to explain what we’re observing in places like Y Combinator.") It would have been nice if he'd cited the reseach which supports this claim.