The UN recently revised its population projections. Some 6.3 billion people now live on Earth. If fertility rates in relatively poor countries continue to follow the trends set by today's relatively rich countries, we are within shouting distance of the world's maximum population-9-10 billion-to be reached in 2050-2100.
But population may well decline thereafter. Literate, well-educated women with many social and economic options in today's rich countries have pulled fertility below the natural replacement rate. The problem is not that such women on average want fewer than two children; in fact, on average they wish to have a bit more than two. But because many of them delay childbearing until their thirties, actual fertility falls short of what they desire.
A world population that peaks at 9-10 billion is not one in which we have to worry about Parson Malthus, the English 19th century economist who prophesied a future in which people multiply faster than the resources needed to sustain them and hence starve to death by the millions. Indeed, it comes as somewhat of a shock to realize that the age of the population explosion may be coming to an end.
Just thirty years ago, people like Stanford University's Paul Ehrlich were telling us that the Malthusian Angel of Death was at the door. They assured us that it was too late to stop the famines that would kill hundreds of millions in the Indian subcontinent, and that humanity's destiny in the 21st century was one of war and struggle for the resources to feed national populations an extra crust of bread.
Today, however, the political flashpoint over food is not that there is too little, but that there is too much. Developing-country politicians and populations complain bitterly that the rich industrial countries are growing too much food.
"Exporting food is one of the few ways we can earn the foreign exchange we need to buy modern industrial technology," they say. "But your agricultural subsidy programs block us from establishing any sort of comparative advantage in most agricultural products. You say free trade is good in those manufactures that you export-you say that enforcing property rights is critically important for your investors-but somehow you go deaf when the topic turns to a level playing field in agricultural trade..."
They are right. Not every developing country can grow rich by making and exporting computer chips, or plastic toys, or bananas. Some need to export steel. Others will have to export furniture or textiles. Still others will have to export citrus, grains, processed foods, etc. Yet there has been little forward motion in opening up world trade for nearly a decade. Given the complexion of the US Democratic Party's key constituencies, this is not surprising. On the contrary, what is surprising is that President Clinton was so willing to swim against the tide generated by his own labor/protectionist base in 1993 and 1994 and establish NAFTA and the WTO.
It is also very surprising that the post-2000 Republican administration of George W. Bush has been so hostile to freer trade. Indeed, Bush has backed several major anti-liberal initiatives: a steel tariff, the expansion of agricultural subsidies, and a declaration that FTAA [Free Trade Agreement of the Americas] negotiations cannot even consider the impact of US agricultural subsidy programs on trade.
Blockages to world trade jeopardize global economic development. Technology transfer is incredibly difficult. It may well turn out that $4 worth of aid are a poor substitute for even $1 worth of exports, because there are few better schools in which to internalize the organizational forms and technologies built since the start of the Industrial Revolution than the school of exporting.
If global development is at risk, then so is the final defeat of Malthus. If the poorest countries stay poor, their rates of population growth might fall much more slowly than the United Nations predicts.
Falling birthrates depend on a rise in the status of women, confidence in public health, growing prosperity, and strong cultural cues to convince people that there are other, better indicators of success than a large family. The fact that most countries are completing the demographic transition does not guarantee that all will. Perhaps Malthus will rule again, in geographically small but densely populated and immensely poor parts of the globe.
The world's high- and middle-income countries should not imagine that the relatively rich can fence themselves off indefinitely from poverty and misery in the poorest countries. Nationalism has long been a powerful cause of political violence. Nothing is more likely to strengthen nationalism and turn it to violence than a sense that one's own homeland is being exploited-kept poor and powerless-by other nations to satisfy their own selfish interests. The world today is too small for any of us to be able to afford for any corner of it to be left out of the conquest of Malthusianism.