Sex and happiness
Despite Chris's warning , I went to Tim Worstall's book launch today. I even bought a copy which I will review on here when I have read it (on the bus tomorrow). But before that, I learned something nice from his answer to an audience question. Apparently, there's a clear relationship between GDP per head and population growth. We already know that people in poorer countries have more children, and the population of those countries grows faster. It seems that there's a measurable cut-off point: at $16,000 per head of GDP, fertility drops to around replacement rate (just over two children per mother) and the population stabilises. Which reminded me of another statistic I read recently: national happiness grows with GDP until a certain point, at which it levels off and people stop getting happier. That level? $17,000 per head *. Now perhaps there's something important in that $1,000 difference, but the two figures are within the margin of error for cross-coun