Plenty of emails in response to that exchange yesterday with Iain on overpopulation, mainly taking Iain’s side. While I’ll never tangle with the great man on his numbers (“Iain Murray is the Barry White of statistics,” J. Goldberg), I’ll stick with my view that we are living on an overcrowded planet. Yes, I’m sure that we could all crowd into Texas, the Isle of Wight, or wherever, if we so choose, but that begs the question as to where the resources for that population is going to come from, and what extracting those resources is going to do to the environment.

And, yes, yes, in reply to the various correspondents who asked, I am well aware that Malthus would be amazed by that the world can manage (sort of) to sustain today’s population, but before dismissing the old boy as completely muddle-headed, we need to remember the famines that the planet has seen over the past century or so. Not all of them were the products of war or communism. Do I agree (with Iain) that relying on the creative energy of the free market is the best way to tackle the challenge of population growth? Absolutely. Is it a sure thing to deliver the goods? Absolutely not.

I do think, however, that if we can avoid adopting policies deliberately designed to increase population size, it would be a good idea. Iain suggests that a (possible) shift to natalism is confined to a relatively small part of the globe. I’m not so sure. We can see its traces (often accompanied by lectures on the desirability of mass immigration) in Europe, North America, Russia, Japan, and, some China-watchers are beginning to suggest that that country too may have to contend with the supposed demographic crisis caused by an ageing population…