The extent of the UK’s ability to trade and conclude trade agreements if it leaves the European Union has become a central argument of the Brexit debate. It has become a standard nostrum of the Remain side that if we left the EU we would need to negotiate numerous trade agreements to prosper, not least with the EU itself. But the nostrum is just nonsense.

Consider how trade works. The UK produces goods in a competitive world market; the prices for these goods are set by world supply and demand.

The UK is also a relatively small supplier in any particular world market, accounting for around 3pc of world GDP. As a result The UK is a 'price-taker’: whatever it sells or buys on the world market has no effect on the world price. This world market can be thought of as a business-to-business market for goods and services at the border or ex-factory. For example a laptop computer of a certain power and with a bundle of typical characteristics would be priced in this market at a certain value, set so that world demand equals world supply; if the UK produces such a machine it would get the same price for it as one produced by, say, South Korea.