Global trends: Population growth, but falling birth, fertility rates

In its "medium variant" projection, the UN Population Division forecasts that world population, currently around 6.1 billion, will rise to 9.3 billion in 2050 and keep growing. But according to Ben Wattenberg, senior fellow at the American Enterprise Institute, what's more likely is that world population will peak at around 8 billion about the year 2030 and then start to decline (perhaps precipitously). The difference is that the UN's "medium" assumptions are too high, says Wattenberg; the overwhelming demographic story of our time, he writes, is that "never have birth and fertility rates fallen so far, so fast, so low, for so long, all over the world, yielding populations in decline."

Consider: the United States is now the only industrialized country in the world with a fertility rate at or above replacement level (the 2.1 births per women per lifetime required for population stability). Fertility rates in less developed countries have dropped dramatically over the last 40 years and now average 3.6 children, compared with only 1.6 in more developed countries. In fact, there are already 21 less developed nations that have fertility rates below replacement level, including Mexico, China and Thailand. Several others' rates have fallen rapidly to near replacement level and continue to drop: Brazil, from 6.25 to 2.25; Turkey, from 6.9 to 2.2; Tunisia, from 7.2 to 2.3; Indonesia, from 5.6 to 2.7.

What we are witnessing globally (and will be witnessing over coming decades) is the "demographic transition," the shift from high birth and death rates to low ones. This transition accompanies (or follows) other transitions of modernization: the economic (to freer markets); the social (to greater female autonomy); the political (to more pluralism); and the technological (to greater information availability). Population projections that do not sufficiently account for these changes are mere extrapolations.

In any case, writes Nicholas Eberstadt (also a fellow at AEI), 4 population trends are certain:

* Global aging. An unprecedented and virtually unavoidable aging explosion will shake and shape rich and poor nations alike. All around the world, enhancing the potential of older citizens to contribute economically will almost surely be a key to material progress in the decades ahead.

* The decline of the West. The current total fertility rate for Western countries is 1.57; over the next 50 years population decline is a certainty in these more developed nations. The ratio of population in less developed countries to that in more developed countries will have moved from 2:1 in 1950 to 6:1 in 2050.

* The eclipse of Russia. One of the world's lowest fertility rates (1.14), combined with appalling mortality levels, spell a plummeting population for the Russian Federation over the next 50 years. From sixth most populous today (at 146 million), Russia would be only number 17 in 2050 (at 104 million), with only half as many working-age adults.

* American exceptionalism. Thanks to (relatively) high fertility and (relatively) high levels of immigration, the US is set to chart a different course from the rest of the Western world over the decades ahead. Total population will grow instead of decline (from 283 million today to perhaps 397 million in 2050), and will not age as quickly (a median age going from 36 to 41, compared to 49 in the rest of the West by 2050).

Today America is the world's third largest country; 50 years from now, it will still be third (after only India and China). But in relative terms, the US will be significantly larger than the European Union and four times the size of Russia or Japan. America's prospects would seem to support, or even enhance, US global influence in the 21 st century.