Women, lamented Hillary Clinton in an April 2014 tweet, make just 77 cents on the dollar to men. As a presidential candidate she has repeated that lament again and again, updating the numbers, in line with government statistics, to 78 cents in July 2015 and 79 cents this year.

This injustice, she says, must be remedied by government. “Last time I checked,” Clinton told an event sponsored by a “salary site” called Glassdoor, “there’s no discount for being a woman. Groceries don’t cost us less, rent doesn’t cost us less, so why should we be paid less?”