He’s heard something and decides to reference it:
As far as basic economics is concerned, they endlessly deny the existence of gravity.
The gravity model of trade. Of course, as with anything vaguely heard of he doesn’t understand it. The gravity model works on economic distance, not geographic.
To explain this to him with reference to his home town, Frome. Somerset coal (largely from around Radstock and Faringdon Gurney) was cheaper in Bristol – heck, in London – than it was in Frome, a place geographically closer. Because there were canals – Somerset Coal Canal, Kennet and Avon (meeting just by Avoncliff) – connecting those places and the Dorset and Somerset, running through Frome, was never completed.
The Dorset and Somerset Canal was a proposed canal in southwestern England. The main line was intended to link Poole, Dorset with the Kennet and Avon Canal near Bradford on Avon, Wiltshire. A branch was to go from the main line at Frome to the southern reaches of the Somerset coalfield at Nettlebridge. Construction of the branch started in 1786, using boat lifts rather than locks to cope with changes of level, but the company ran out of money and the canal was abandoned in 1803, never to be completed.
That’s economic distance and that’s what the gravity model of trade depends upon, not geographic distance.
Shouldn’t be too, too, hard on Harris of course for most commentators don’t grasp this either. Sadly so.