That nagging question again: Why aren’t there more women in power? They’re in Fortune 500 companies, finance and Big Law—except they’re still woefully underrepresented at the top. At major law firms, women’s equity partnership rates have barely moved, hovering forever, it seems, between 16 and 17 percent.

Is it plain sexism that’s keeping women down? Or are women making a choice to get out of the race?