The Demographic Transition

Introduction The Demographic Transition was originally proposed in 1929 by Warren Thompson. It attempts to account for changes in population growth within a society over the course of economic development from a pre- industrial to an industrialized society.

Introduction The original model was developed on the basis of observing historical changes in the population of industrialized western nations over the past two centuries.

Introduction Before examining the model, a review of specific vocabulary is necessary.

Introduction Birth Rate - births in a given year for every 1000 persons. Death Rate - deaths in a given year per 1000 persons.

Introduction Natural Increase – The natural change in population is the difference between births and deaths. It does not include the effects of migration.

Introduction Fertility Rate – the average number of children that would be born to a woman during her lifetime. Doubling Time – the number of years it will take to double the present population given its present rate of growth.

Introduction Population Pyramid A bar chart that shows the age and sex distribution of members of a population. Source: United Nations Population Division Department of Economic and Social Affairs

The Demographic Transition Source:

The Demographic Transition Population Pyramids for Each Stage Source:

Stage 1 Characteristic of a pre- industrial society experiencing both high birth and high death rates. Infant mortality is very high.

Stage 2 There is a decline in death rates and an increase in population. Historically, these changes occurred as a result of the Agricultural Revolution in Europe in the 1700’s.

Stage 3 Characterized by a decline in birth rates and death rates. These changes are the result of fewer children being needed to help on farms. improvements in medical technology help increase life spans. a shift from rural dominance to increasing urbanization.

Stage 4 Characterized by low birth and death rates, the population is stabilizing. There is almost equal replacement within the population (birth rates equal death rates). The society is fully industrialized and predominantly urban.

Stage 5 - Proposed Characteristic of a post- industrial society, there is a progressive decline in birth rates (sub-replacement fertility) and death rates continue to decline leading to an aging population. This has great ramifications as there are fewer younger people available to fill the work force. Some European nations, such as Germany, are currently experiencing this phenomenon.

Criticism Because the model is based on population change in developed or industrialized nations, it’s applicability to the developing world is limited. The model does not consider the effect of social changes, such as the education of women, on birth rates.