They must learn to adapt. The growing equality of the sexes is one of the biggest achievements of the post-war era: people have greater opportunities than ever before to achieve their ambitions regardless of their gender. But some men have failed to cope with this new world. It is time to give them a hand.
Policymakers also need to lend a hand, because foolish laws are making the problem worse. America reduces the supply of marriageable men by locking up millions of young males for non-violent offences and then making it hard for them to find work when they get out (in Georgia, for example, felons are barred from feeding pigs, fighting fires or working in funeral homes). A number of rich countries discourage poor people from marrying or cohabiting by cutting their benefits if they do.
Part of the solution lies in a change in cultural attitudes. Over the past generation, middle-class men have learned that they need to help with child care, and have changed their behaviour. Working-class men need to catch up. Women have learned that they can be surgeons and physicists without losing their femininity. Men need to understand that traditional manual jobs are not coming back, and that they can be nurses or hairdressers without losing their masculinity.