Thursday, November 03, 2011
Who's Afraid of Seven Billion People?
This Halloween, the United Nations declared over the summer, a baby will be born somewhere on Earth who will tip the world's population over seven billion for the first time. Truly do international bureaucrats have the power of prophecy! The precision is bunk, of course, or rather a public-relations gimmick. Nonetheless, the occasion will provide an excuse for yet another round of Malthusian gnashing of teeth about overpopulation. But we shouldn't let it obscure the real story of the past 50 years, which is not how much faster than expected, but how much slower, population has been growing. The growth rate of world population has halved since the '60s and is now expected to hit zero around 2070, with population around 10 billion, though some news outlets prefer to focus on the U.N.'s "high" estimate that it "could" reach 15 billion. The truth is, nobody can know, but if it's below 10 billion in 2100, we will have only increased in numbers by 1.5 times in the 21st century, compared with a fourfold increase in the 20th. This "demographic transition" to lower birth rates began in Western Europe in the 19th century and later spread to North America, then Latin America, Asia and now Africa. In 1955, the birth rates per woman in Yemen, Iran, Bangladesh, Nigeria, Brazil and China were, respectively, 8.3, 7.0, 6.8, 6.5, 6.1 and 5.6. Today they are 5.1, 1.7, 2.7, 5.2, 1.8 and 1.7. Notice: The poorer a country has remained, the slower the fall. The fall in the birth rate is a largely voluntary phenomenon. It has happened just as fast in countries with no coercive population policy as it has in China, with its Draconian two-child law. The demands for coercion that were common in the 1970s—"Why should the law not be able to prevent a person from having more than two children?" wrote Paul Ehrlich, Anne Ehrlich and John Holdren in 1977—seem embarrassing in retrospect. Birth rates have gone down because of prosperity, not poverty. Everywhere it has occurred, it has followed a fall in child mortality and famine and an increase in income and education...more