As the United Kingdom continues to be gripped by the great Brexit debate, and will be so for many months to come, a surprising statement comes from the chief economist of the Bank of England, Andy Haldane. It is the Haldane view that leaving the European Union single market will have little material effect on the British economic growth — at least for the next three years.

But how can this be? Surely the whole debate has revolved round the damage that would supposedly be done to British business and exports by being denied access to the single market, with all its protective tariff walls, its standards and regulations. Will not the daily flow of goods, components, processes and personnel between Britain and the rest of the continent be fatally interrupted and penalized, cutting off British exporters from what is said to be the world's largest single market area?

Or is it possible that this highly esteemed expert has perceived something about the nature of modern trade which has escaped the more excitable politicians and their advisers?