POPULATION GEOGRAPHYPopulation Theories

Demographic Transition Model

Population Theories

•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.

BUT REMEMBER…

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 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.

AGE-SEX STRUCTURES

Population Pyramids

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!

Demographic Transition Model

Predicting Populations

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.

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