The rich countries, on their part, could do themselves and the world a huge favour by putting their efforts into reducing their greenhouse-gas emissions and following through on promised aid, including for universal access to family-planning services, rather than on raising their own fertility rates.

ECONOMIST: On Phoenix, Claus Schenk von Stauffenberg, global population growth | The

The reality means more than 350 million couples still lack access to a full range of family planning services, and 529, 000 women die annually from complications of pregnancy and childbirth, most of them preventable.

BBC: NEWS | Science/Nature | Slowing population 'lacks funds'

And in Iran, public policy and investment in family-planning services made the difference between rising fertility between 1979 and 1984 and falling fertility thereafter, not the rise in national incomes, nor female education.

ECONOMIST: Population booms, and busts