Here’s something that no one ever explains. If American women earn 18.1 percent less than American men, as the OECD has just revealed, why does anyone employ men? If you had two similarly qualified applicants, one of whom was asking for a significantly higher salary, you’d hire the cheaper one, wouldn’t you?

Likewise, if having more female directors significantly boosts share performance, why do companies need to be told to appoint more female directors? Private firms are interested in profit, after all. If there is a large pool of undervalued women out there, surely, entrepreneurs will spot the opportunity.