We have just passed the 200th anniversary of the great work by David Ricardo, the British classical economist, a work that did more than any other to explain the benefits of free trade. We are also just approaching the 200th anniversary of the birth of Karl Marx, but I shall leave him for another week.

Ricardo’s theory of comparative advantage, contained in his Principles of Political Economy and Taxation, demonstrated that two countries, in his example England and Portugal, benefit from trade even when one is more efficient at everything than the other.

As a very rich economist, Ricardo owned a string of properties, including Gatcombe Park, better known these days as the country home of Princess Anne.

I mention Ricardo because we are at