Sometime in the next few years (if it hasn’t happened already) the world will reach a milestone: half of humanity will be having only enough children to replace itself. That is, the fertility rate of half the world will be 2.1 or below. This is the “replacement level of fertility”, the magic number that causes a country’s population to slow down and eventually to stabilise. According to the United Nations population division, 2.9 billion people out of a total of 6.5 billion were living in countries at or below this point in 2000-05. The number will rise to 3.4 billion out of 7 billion in the early 2010s and to over 50% in the middle of the next decade. The countries include not only Russia and Japan but Brazil, Indonesia, China and even south India.
The biggest change? Iran, where the average fertility rate dropped from seven(!) in 1984 to 1.9 in 2006 (1.5 in Tehran).
Lastly, a special case: China’s one-child policy, which began nationwide in the early 1970s. China’s population is probably 300m-400m lower now than it would have been without it. The policy (which is one of population control, not birth control) has had dreadful costs, including widespread female infanticide, a lopsided sex ratio and horrors such as mass sterilisation and forced abortions. But in its own terms, it has worked—20m people enter the workforce each year, instead of 40m—and, to the extent that China is polluting less than it would have done, it has benefited the rest of the world.Read the whole thing. I do not at all agree with that last statement. For every person not born, there may be less pollution. But there is also less production, less trade, less innovation, and less love. To look only at a reduction of costs and not at a reduction of benefits is engaging in some faulty economic analysis. On a more human level, when was the last time you heard someone try to comfort a parent who just lost a child: "Well, just think of all the pollution we won't have?"
As Scott Lamb points out, how you view this decrease in worldwide fertility depends strongly on your worldview. Lamb is quite happy to have five kids waiting for him when he gets home. I wonder how many parents in China would envy his position?
See my previous posts: