That being said, though, I don’t know that this is anything other than a marginal phenomenon. Darien, CT, and certain small slivers of NYC aren’t the whole story, by any means. It reminds me strongly of a story in the London Times a few weeks back. (http://women.timesonline.co.uk/tol/life_and_style/women/families/article1967563.ece)

It means it’s August in the media world.

But in the past 10 years, the number of high-end earners who are having three or more kids has shot up nearly 30 percent.

What percentage of the population does this group consist of? What percentage of the population in their income bracket do “competitive birth” families consist of? If this group is 1,000 strong nationally then a 30% increase wouldn’t be noticeable let alone qualify as an important social phenomenon.

With regard to historian Gregory Clark’s ideas about the foundation of the Industrial Revolution, Dr. Clark admits to one puzzling inconsistency: “the Samurai in Japan and the Qing dynasty in China, were surprisingly unfertile”.

Unless Dr. Clark can come up with some reason to think the effect of downward social mobility was suppressed in China and Japan, what’s the reason it didn’t show up everywhere else there was any sort of income disparity? Shouldn’t there have been heaps of Industrial Revolutions? I think it’s pretty obvious that some other factors were pivotal, not the greater infant survival rate of the wealthy.

Dr. Clark is also dizzyingly wrong about Malthus. Malthus repudiated his earlier notions about population growth and agricultural output since, within his lifetime, there was a considerable increase in population that went hand-in-hand with with a drop in food prices and an increase in variety. Ever since, Malthusians have, uniformly, been fortune tellers rather then historians since the history of Malthusian resource collapses is empty. It’s always just around the next corner and always has been.