Sometimes it’s because they’re stupid and lazy, too.
When you control for such factors as education and hours worked, there’s actually just a 5 percent pay gap. But the AAUW isn’t going to begin a report with the statement that women earn 95 percent of what their male counterparts earn, is it?
…women choose fewer hours—despite the resulting gap in earnings—all over the world. That includes countries with generous family leave and child-care policies. (…)
So why do women work fewer hours, choose less demanding jobs, and then earn less than men do? The answer is obvious: kids. A number of researchers have found that if you consider only childless women, the wage gap disappears.
June O’Neill, an economist who has probably studied wage gaps as much as anyone alive, has found that single, childless women make about 8 percent more than single, childless men do (though the advantage vanishes when you factor in education).
It isn’t just kids, though.
Women also work less hours because they spend more time crying in the bathroom/taking “sick days” than men: