NO. 5
Splits in Demographic Transition Theories and New Concepts (2)

Toshio Kuroda

1) Polarization of Demographic Transition Theories

American and European scholars made historical analyses of vital statistics from Britain that had taken a typical modernization process, and other European countries that followed. They found that the process of demographic transition followed distinct stages, and they suggested the possibility of a universal law of historic similar demographic development. This law was widely accepted in demography, sociology and economics.

F.W. Notestein, who conducted "population projections of Europe and USSR" after World War II, presented his hypothesis of three stages of demographic transition. Today, half a century later, his assumption of the "incipient decline" stage is being proven as population decline is occurring in all countries under the influence of western European culture. It is noted that Notestein had a brilliant insight.

There is a criticism against the demographic transition theory. The theory was devised from the universal law discovered through the analyses of historical demographic changes in countries with western European culture. After World War II, however, some countries outside this cultural sphere, such as some in Asia and Latin America, underwent a rapid process of demographic transition.

Therefore, the question is how cultural differences affect the process of population decline, or whether demographic transition outside the European cultural sphere could be understood to be the same in quality as that which had happened in Europe.

2) Tri-poles of fertility order

When the patterns of demographic transition of world population are observed as total fertility rates (TFRs), it is found that fertility can be categorized into patterns. According to the classifications by the UN Population Division, fertility is classified into four stages: under-replacement level of countries whose populations are on the decline, countries with low TFRs between 2.2-2.9, countries with rather high TFRs between 3.0-4.9, and countries with the highest TFRs between 5.0-7.5.

Between 2000 and 2050, the world population will gain 3 billion, from 6 billion to 9 billion, or increase by 60 million on average every year. World population is projected to stay at the same level, in other words, the world will see its population become stationary in the latter half of this century and onwards. However, it should not be ignored that the rapid population increase is due to occur in the early half of this century.

The patterns of demographic transition are quite different among countries and regions as far as fertility levels are concerned. In particular, great disparity in population change can be observed in this century.

First, a remarkable demographic decline is going on in countries under western European culture. TFRs in Europe and North America are all under 2.1, and the proportion of the total population of these two regions will fall from 17 percent to 12 percent in the first half of this century.

Second, the population of Asia with quite high TFRs is estimated to increase by 1.5 billion in the same period. It will be a great part of the increase of world population.

Third, the TFRs in Africa are staying at the highest level in the world, and a one billion population increase is estimated in half a century.

Even though the populations of Europe and North America will decrease, the size of the decline is only 100 million or so, and the portion in the total population will fall only from 17 to 12 percent. Considering the extraordinary increases and changes in regional populations in the first half of the century from current socio-economic conditions and from a geopolitical point of view, I cannot help feeling surprised at the seriousness of the impact.

3) The greatest population crisis and tasks
to cope with demographic transition

Population explosion must be approached from two aspects. One is a global strategy to consider it as a process of the sharp increase expected in the first half of the 21st century. The other is the impact of imbalances in speed and scale of population increases by regions on global society.

A perspective of further importance is a basic theoretical analysis on demographic transition. The traditional demographic transition theory developed along with modernization processes has now lost its universal meaning. Countries in the western European cultural sphere are now going out of the final stage of classic demographic transition. The role of "population" in demographic transition is greatly changing.

Without understanding newly emerging functions of “population,” humankind cannot be successful in its challenges.