I expect we're all wearily familiar with the population prodnose. Those who comment (most often seen at Comment is Free but they do spread themselves around a bit), endlessly, along the lines that "this is the problem that cannot be mentioned, the rising population". And who then go on to suggest the compulsory sterilisation of anyone a little browner than they think people ought to be. With rather fewer fascistic overtones we get similar stuff from people like Johnny Porritt and the Optimum Population Trust. There's just too many people, too many of them are peasants who won't do what Baronets tell them to and it's all just appalling.

Very strangely indeed it's largely these same people who insist that there must be a plan to deal with this population thing. Despite the fact that population is one thing that free markets deal with very well indeed thank you very much. As Ron Bailey over at Reason points out:

The crucial point is that increasing economic liberty correlates with increasing life expectancies, and thus falling fertility rates. As data from the Heritage Foundation’s Economic Freedom Index shows, average life expectancy for free countries is over 80 years, whereas it’s just about 63 years in repressed countries.

The causal chain is as follows: economic freedom increases wealth: increased wealth leads to longer lifespans. Longer life spans for women reduce fertility rates (I know, you might think it works the other way: but it doesn't). Therefore economic freedom reduces population growth.

And there we have it: we don't need grand plans to sterilise everyone a racist wouldn't like to bring home to mother for tea. We don't need to pressure the peasantry into doing what an Old Etonian thinks they ought to. We just have to leave people to get on with it themselves. People generally like economic freedom, they certainly like increased wealth and longer lifepsans and the end result of all three is that population growth falls, falls to below replacement rate and thus the gross population falls over time.

No plans, no pressure, no coercion, just free markets and the rule of law saving the planet. Great, eh? Now if only we could get the population prodnoses to understand this....