The National Bureau of Economic Research has just released a working paper arguing that pregnancy rates predict whether the economy is going to fall into recession in the near future.

It’s worth considering what a recession is. Different schools of economics will varyingly insist that this or that causes them, or even that they cannot happen at all — those latter ones are wrong. One part where John Maynard Keynes was right is that they come about because of a change in confidence (Well, some of them do). For it is true that if we all think the future’s going to be gloomy, then it will be so.