why is there a gender wage gap?

Left-leaning Vox has its take.

Right-leaning (well, libertarian) Foundation for Economic Education (FEE) has its take.

I actually have trouble seeing how the above articles are contradictory. The Vox article pins the problem largely on the choices women make after giving birth:

Much of Kleven’s paper is designed to untangle what exactly happens after women have children that leads to this wage gap. He finds that women start to gravitate toward different jobs after the birth of a child, ones with fewer hours and lower wages. Ten years after childbirth, women have a 10 percentage point higher probability of public sector employment than men. These are jobs that typically offer “flexible working hours, leave days when having sick children, and a favorable view on long parental leaves.”

The above-linked FEE article takes the standard position that the wage gap can be explained purely as a function of the career choices women make. In essence, women are the cause of their own wage-gap problem. Want to earn as much as a man? Well, what's stopping you from training to be a doctor or a lawyer or a construction worker? Plenty of women are in these fields, but "plenty" doesn't mean that these fields comprise 50% women. Why is that, ladies? Could it be because biology really does matter, despite the current feminist propaganda?