Demographic Transition Theory

Abstract

Although it dominated demographic thinking in the latter half of the twentieth century, the demographic transition theory actually began as only a description of the demographic changes that had taken place over time in the advanced nations. In particular, it described the transition from high birth and death rates to low birth and death rates, with an interstitial spurt in growth rates leading to a larger population at the end of the transition than there had been at the start. The idea emerged in 1929, when Warren Thompson gathered data from “certain countries” for the period 1908–1927 and showed that the countries fell into three main groups, according to their patterns of population growth: (1) Northern and Western Europe and the United States had gone from high rates of natural increase to very low rates of natural increase, and were on the verge of depopulating at that time; (2) Italy, Spain, and the “Slavic” peoples of Central Europe showed some evidence of a decline in both birth rates and death rates but it seemed likely that the birth rates would remain higher than the death rates for some time to come; and (3) the rest of the world, where there was little evidence of control over either births or deaths. These latter countries, comprising about 75% of the world's population at the time, were “determined largely by the opportunities they have to increase their means of subsistence. Malthus described their processes of growth quite accurately when he said ‘that population does invariably increase, where there are means of subsistence … ‘” (Thompson, 1929:971).