If scarcity imparts value, male babysitters have it all figured out.

Less than 3 percent of all babysitters are men, the economics blog Priceonomics has found, but they still earn more than their female counterparts. Hiring a local young man to watch your kids will cost you an average of $15 an hour (there's a lot of regional variation), but the going rate is just $14.50 for the same services provided by a young woman.

Screenshot: Priceonomics

Granted, the source is "Priceonomics Data Crawling," which is a little opaque. Still, if accurate, this data shows that the gender-wage gap penetrates even the most feminine of feminized professions. It's not just babysitting: One study from the Institute for Women's Policy Research, for example, showed that even female administrative assistants, teachers, and nurses—three fields that are dominated by women—still make less than their male colleagues by about 10 percent.

The Priceonomics post's author, Rohin Dhar, speculates that this could be because men are more confident and thus can negotiate higher wages. The other possibility is that there are so few male babysitters that the ones who are drawn to this sort of work are uniquely qualified in some way—maybe they're beloved, master fort-builders, for example, or actual child-rearing specialists.