Box 1 - Birth and Death Rates, 1770-1980

In the industrialized nations in the last century, the declining death rate was accompanied by a decline in the birth rate. From a rate of about 40 per 1000 in 1875, the birth rate in developed countries went down to about 20 per 1000 by 1970. Demographers refer to this gradual shift in both birth and death rates as the "demographic transition."

The difference between the birth rate and the death rate is a measure of how fast the population is increasing. For developed countries, this difference is about 10 per 1000 population, or about 1%. This means that, despite going through the demographic transition, developed countries continue to grow in population.

In a large number of developing countries the birth rate continues to be close to 40 per 1000, while the death rate has fallen to about 15 per 1000. This results in an increase in population of 25 per 1000 each year, or a 2.5% population growth rate.

A number of developing countries have experienced significant declines in birth rates in the 1960s and 1970s. In Cuba and Taiwan, for example, the birth rate is now approaching 20 per 1000.