Population Theories Demographic Transition Model Population Geography Population Theories Demographic Transition Model

Population Theories

BUT REMEMBER… The agricultural revolution allowed for cities and faster population growth rates (10,000-12,000 years ago). The Industrial Revolution allowed for even faster growth rates (starting in the 1700s). Earth has experienced a POPULATION EXPLOSION in the last 2-3 centuries.

Thomas Malthus Economist and geographer Essay on the Principle of Population (1798) Claims based on: 1.) People need food to survive 2.) People have a natural desire to reproduce Food production increases arithmetically (linear growth) while population grows geometrically (exponential growth).

Thomas Malthus Argued that human population growth would eventually outpace people’s ability to produce food. This little problem would lead to war, starvation, and disease, or “negative checks” on the population. Advocated for “positive checks” such as birth control and celibacy.

HAS THIS HAPPENED?

Arguments against Malthusian perspective Malthus did not fully account for the ability to people to increase food production dramatically with new agricultural technologies. Genetic engineering Improved fertilization techniques Modern farm equipment

Arguments against Malthusian perspective (continued) Did not foresee population growth would slow down over time. Contraception Changing role of women Individual choice of not having children Did not recognize famine is usually not related to lack of food, but to the unequal distribution of food.

Neo-Malthusians Apply some ideas in the Malthusian theory. Human population growth must reach a “sustainable” level within carrying capacity. Regional rather than global.

Paul Ehrlich The Population Bomb (1968) Neo- Malthusian ecologist Made the argument about the ability of the earth to sustainably provide resources for an exponentially growing population. Mass starvations Societal uprisings Raised the general awareness of population and environmental issues and influenced public policy. The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate...

Other theories… Karl Marx Ester Boserup Population growth rates are not the problem but the unequal distribution of resources and wages would eventually lead to class warfare. Ester Boserup Believed that the overpopulation problem could be solved by increasing the number of subsistence farmers.

Population Pyramids AGE-SEX STRUCTURES

Population Cohort A group of people that all have something in common and are usually grouped together for statistical purposes. In population pyramids, each cohort is split between men and women.

Population Pyramids A model used in population geography to show the age and sex distribution of a particular population.

Shape matters… Wide-base= more young people Top-heavy= more old people Tells you about the current population and can give you information about the FUTURE!

Predicting Populations Demographic Transition Model

Several models have been developed to explain changes in population over time and to relate various social, economic, and environmental factors to population growth.

Demographic Transition Model Explains changes in the natural increase rate as a function of economic development.

Demographic Transition Model

Three measurements used in the DMT Crude birth rate (CBR) Crude death rate (CDR) Natural increase rate (NIR)

Stages of “Transition” Stage 1, Low Growth Stage 2, High Growth Stage 3, Moderate Growth Stage 4, Low Growth

Stage 1, Low Growth (High Stationary Stage) High CBR and CDR. Natural increase rate essentially zero. During this stage, most people depend on hunting and gathering for food. Subsistence farming country without an industrialized economy.

Stage 2, High Growth (Expanding Stage) Crude death rate suddenly plummets, while crude birth rate roughly remains the same. Children are needed on farms (high CBR). New health care systems arrive (medicine) and industrialization has begun (lowered CDR). Therefore, the natural increase rate is also very high, and population grows rapidly.

Stage 3, Moderate Growth (Expanding Stage) Crude birth rate begins to drop sharply. The population continues to grow because the CBR is still greater than the CDR, but the increase is more modest. People choose to have fewer children. Population more likely to live in cities and to work in offices, shops, etc. rather than farms. Children will live longer because of new health care technology available. Women have more options in newly industrialized economy.

Stage 3, Moderate Growth (Expanding Stage) Crude birth rate begins to drop sharply. The population continues to grow because the CBR is still greater than the CDR, but the increase is more modest. People choose to have fewer children. Population more likely to live in cities and to work in offices, shops, etc. rather than farms. Children will live longer because of new health care technology available. Women have more options in newly industrialized economy.

Stage 4, Low Growth (Low Stationary Stage) Crude birth rate declines to the point where it equals the crude death rate Zero population growth or very low NIR. Modern-society stage.

Stage 5 (Proposed) Would show a continuing decline in the CBR Seen in more- developed countries such as France and Germany.

UNIVERSALLY Applicable????? Is the Demographic Transition Model UNIVERSALLY Applicable?????

Arguments against DTM Too simplistic Eurocentric model? Factor such as culture, religion, geopolitics, migration, and the structure of the global economic system itself may prevent many of today’s less developed countries from ever taking the path described. More people today. Economies transitioning way faster now. Regional differences