As David Ricardo pointed out, if we all do what we’re least bad at and trade the results then we’ll be better off. That is what the lesson of comparative advantage is, yes. Forget the cloth and wine, that it’s between countries and all that. Whatever assets there are lying around should be put to their best - least bad - uses and then we swap around the resultant higher production. Division and specialisation of labour and the resultant trade from Smith, Ricardo telling us how that division should be logically underpinned.

At which point, something about Morocco wanting to become a renewables superpower or something:

Morocco also plans to harvest bright Saharan sun through conventional solar panels. These can generate three times as much power in the North African country than they would in the UK.

So, the solar panels should be in Morocco not on the north facing roof of some building in Hebden Bridge then. For whatever amount of money - or subsidy - spent on solar panels we’d get three times the electricity, we’re richer.

This is not, clearly not, how public policy actually works currently. We’re bombarded with insistences that Britain must produce the power that Britain consumes. That local power delivered locally is better.

Note that this is nothing, nothing at all, to do with renewables or fossil fuels. The logic is that whatever it is that we use as a power source should come from whoever, wherever, is most efficient at producing the power we intend to use. Local makes us poorer, trade makes us richer.

So, to be richer we should trade. Given that that is the opposite of the current political and cultural insistence we are left with the one big question. How on Earth did the entire society end up getting this so wrong?