“Consumption is the sole end and purpose of all production.” Thus taught Adam Smith. It is hard to see what else production is for, now or in future. Consumption must be the goal of international trade, too. But what happens if significant players do not seem to believe this? Then the global system malfunctions.

The starting point here needs to be with a proposition fundamental to the economics of John Maynard Keynes: actual spending activates potential savings. Moreover, he argued, there is no reason to believe that the needed spending will happen naturally. He called this “the paradox of thrift”. Sustaining high levels of activity may demand policy action.

Today, the structural excess savings of a number of economies, notably China, Germany and Japan, are largely offset (and so activated) by the excess spending of the world’s most creditworthy country, the US, (and, to a lesser extent, the UK). The figures are startling. Just these big three surplus economies ran aggregate current account surpluses of $884bn in 2024. The surpluses of the top 10 countries amounted to $1.568tn. But surpluses are only made possible by deficits. Thus the US ran a current account deficit of $1.134tn, to which the UK added $123bn. (See charts.) Donald Trump’s presidency is, in part, a symptom of this reality.