And indeed, we as a profession are making our voices heard in a way we never get the chance to do when the credit is flowing, businesses are investing and consumers buying what business wants to sell. Then, we make arguments based on data, otherwise known as “facts”, processed through regression analysis and logical rigour, which few humans read. (I know, I am an economics journal editor.) Now, on the other hand, we call for trillion dollar stimulus plans on the basis of little more than citing John Maynard Keynes – and politicians revere us. Citing Keynes gives us special licence to talk economics without using any. To paraphrase the lawyers' dictum, when the facts are on our side, we pound the facts; when theory is on our side, we pound theory; and when neither the facts nor theory are on our side, we pound Keynes – and to great effect.

Keynes, not coincidentally, had nothing to say about the proper components of fiscal stimulus. This allows him to be cited with great effect by both paternal progressives (who favour government spending) and caring conservatives (who favour middle-class tax cuts).

To be sure, economists have published peer-reviewed technical analyses of the efficacy of government spending and tax cuts. But when nature fails us we console ourselves with Scripture, not science, and when markets fail us we turn to Keynes. His famous quip that “In the long run we are all dead” is a profoundly satisfying justification for borrowing a trillion dollars, right now, never mind that it contradicts an essential insight of our discipline: in the words of Frédéric Bastiat from 1848: “The bad economist confines himself to the visible effect; the good economist takes into account both the effect that can be seen and those effects that must be foreseen” – in other words, the long run.