People power

Forget the idea of an overpopulated world: plummeting fertility rates mean we should be having more children.

- BY MARK FRYER

For as long as I can remember, overpopulation has been one of those Very Bad Things That We Really Ought To Worry More About. True, as issues go, rampant population growth isn't as high profile as it was, but it's still hard to resist the idea that the world’s problems would be easier to fix if there just weren't so many of us.

So it's confronting to be told that a) we can all stop worrying about humanity’s relentless expansion, and b) what we should be losing sleep over is the opposite: fewer and fewer people on Earth.

That's the big message in this slender volume from two University of Texas demographer-economists, Dean Spears and Michael Geruso. They spell it out from their second paragraph: “Birth rates have been falling everywhere around the world. Soon, the global population will begin to shrink.”

Part one of that message is no surprise. Everyone knows birth rates have been declining, and not just in the wealthier Western world. Part two may be more challenging if you were raised on fears of the “population bomb”, but the logic behind it is clear.

The population grows when the average woman has more than enough children to replace herself and a partner. Right now, that magic number is just over two children per woman, to allow for the (diminishing) risk that some won't make it to reproductive age.

But, say the authors, “two-thirds of the world lives in countries where fertility is already below replacement”, including the two most-populous nations, India and China. The birth rate is below two in many other places: about 1.6 children per woman in the US, 1.5 in the EU, just 0.7 in South Korea and Hong Kong and 1.6 in New Zealand.

True, the average fertility rate for Africa is above four, and even higher in some nations, but the trend is the same; a few decades ago, the African rate was more than six children per woman.