Doctors don't really have the equal pay thing down yet

Looks like the gender pay gap is a real issue for doctors, too. Doximity, a professional social network for physicians, is out this morning with a survey that shows women physicians earn an average of nearly 27 percent less than men. It's a survey of the salary data reported by 36,000 of its members.

What's missing: Any explanation of why the pay gaps exist. That's because the survey didn't try to look for causes, which would be hard to pin down anyway, according to the survey's lead author, Chris Whaley of the Berkeley School of Public Health. He said they'll try to dig into that in a later survey — though in other professions, the gender gap is usually caused by a combination of bias, differences in training and background, and differences in negotiating power. "It really begs more questions than it answers," said Doximity's Joel Davis.

Notable: The survey also found huge differences in physician pay between different metropolitan areas, sometimes within the same state. The lesson, according to Davis: "Health care in the United States really is a local market."