Sunday, January 31, 2010

World Population in 2300

(This is a paper I wrote six years ago, before I started this blog. I referred to it in another post above, so I decided to reproduce it here.)

Copyright © Gordon R. Durand, 2004

Falling Fertility Rates

A number of articles have noted the decline in fertility rates in recent years. In much of the developed world fertility rates have fallen below the replacement rate of 2.1, and the population of many countries has begun to decline. Even in the developing world rates have fallen, and the rate of population growth, although still rapid, has begun to slow.

How low can the rate go? The chart below shows the fertility rates for twenty of the most populous countries, accounting for 60% of the world's total population, plotted against the Human Development Index, a quality of life indicator which combines GDP, adult literacy, and life expectancy. The three countries on the chart ranking lowest on the Development Index, Nigeria, Bangladesh, and Pakistan, also have the highest fertility rates: 5.4, 3.6, and 5.1 respectively. The five countries on the chart with the highest Development Index, Germany, the UK, France, Japan, and the United States, all have fertility rates below the 2.1 replacement rate. These countries would even now have declining populations, were it not for immigration.

The ten countries ranking highest on the Human Development Index, Norway, Australia, Canada, Sweden, Belgium, United States, Netherlands, Japan, Finland, and France, have an average fertility rate of 1.6. Twenty-one countries have fertility rates below 1.3, including Russia, Germany, Italy, Spain, and Poland. And five have rates as low as 1.1: Armenia, Bulgaria, Latvia, Macau, and Ukraine.

The Future of Population Growth

With continued economic growth the rest of the world will eventually attain a level of development equivalent to that of the wealthier countries today. Along with higher levels of development we can expect lower fertility rates. With low fertility rates and an aging population, most of the world will find itself in the condition experienced by Sweden, Belgium, and Japan now. Death rates will exceed birth rates, and the population will peak and begin a gentle decline.

How soon will it happen? China today has a GDP per head of only $860, but with an annual growth rate in real GDP of 9.6%, its GDP per head will exceed $36,000 in forty years.

The table below projects the future population of the ten most populous countries. It assumes that birth rates and death rates in each of these countries will attain by 2050 the levels which exist in Sweden today, and hold steady at those levels thereafter.

Population (millions)

Country 2003 2050 2100 2200 2300
------------- ----- ----- ----- ----- -----
China 1,275 1,437 1,274 1,002 788
India 1,008 1,379 1,223 961 756
United States 283 300 266 209 164
Indonesia 212 273 242 190 149
Brazil 170 215 191 150 118
Russia 145 116 103 81 64
Pakistan 141 251 223 175 138
Bangladesh 137 215 191 150 118
Japan 127 122 109 85 67
Nigeria 113 201 178 140 110
------------- ----- ----- ----- ----- -----
Totals 3,614 4,513 4,002 3,147 2,475
World Total 6,000 7,493 6,644 5,225 4,109

The World Total merely scales the total population of these ten countries by a factor of 1.66; it does not represent an actual projection.

Population Implosion Worries a Graying Europe New York Times, July 10, 1998
Europe's population implosion The Economist, July 17, 2003
The Population Implosion Wall Street Journal, April 28, 2004