Tomorrow, to mark the bicentenary of Ricardo’s counterintuitive idea, the Institute for Free Trade, of which I’m president, is holding a conference in the City to explore its full implications. The audience will be made up largely of parliamentarians, civil servants and trade officials from Britain and abroad – precisely the people who, if they were to act according to Ricardian principles, could add trillions to world output.

Even now, our government, like most governments, retains several rusty mercantilist structures that have survived since before we joined the EEC: an export finance agency, marketing boards and the like. We still intuitively believe that exports matter more than imports. In fact, as a study of 160 countries published this week showed, imports and exports rise and fall in lockstep. Imports, by creating greater efficiencies in production, will almost by definition facilitate exports – as well as improving people’s lives. It makes no sense to fret more about the one than the other.

The trouble is that dependency on foreigners offends our hunter-gatherer intuitions. Comparative advantage just feels wrong. When Donald Trump’s administration applied its moronic tariff against Bombardier, it was applauded for “protecting American jobs”. In fact, that tariff will destroy many more jobs in aviation and in the wider economy than it props up at Boeing. Every cabin attendant whose job would have come into existence would have had money to spend elsewhere. Every passenger whose ticket would have been cheaper would have used the surplus to boost other businesses. That now won’t happen.