Demographic – Population Theories

Demographic Transition TheoryMalthusian Overpopulation Theory

Demographic Transition Model

What is it?

Demographic transition is a model used to explain the process of transition from high birth rates and high death rates to low birth rates and low death rates as part of the economic development of a country from a pre-industrial to an industrialized economy. It was first developed in 1929 by the American demographer Warren Thompson who observed changes, or transitions, in birth and death rates in industrialized societies over the past two hundred years.

The Demographic Transition Model

How do we expand this to include Stage 5?

How do we expand this to include Stage 5?

Demographic Transition Model

STAGE ONE: Birth rates and death rates are high. The natural increase gap is small - population grows slowly.

STAGE TWO: Death rate declines and birth rate remains high. The natural increase gap becomes larger – population explosion.

STAGE THREE: Birth rate begins to decline and the death rate remains low. The natural increase gap narrows – population explosion slows.

STAGE FOUR: Birth rate and death rate tend to be low and steady. The natural increase gap is small – slow population growth.

STAGE FIVE: Birth rates drop lower than death rates. The natural increase becomes negative – the population shrinks!

Stage 1

High birth ratesHigh death ratesPopulation growth is therefore staticThis was the situation in much of the world prior to the Industrial Revolution – agricultural societies

Stage 2

Scientific and medical knowledge increases, the death rate drops, but the birth rate remains highThe result is a population explosion

Stage 3

Low death rates and rapidly declining birth ratesGrowth of social programs to support elderly peopleIndustrialization on the farm as well as urbanization cause family size to decline

Stage 4

Low birth rates and low death ratesPopulation growth is stable because no longer want large families

Stage 5

Population declines because death rates exceed birth ratesPeople want to spend money on consumer goods and travel, not kidsExtinction is the ultimate result

Malthusian Population Theory

Overpopulation Theory

Malthusian Theory:

– His argument was that human population grows much faster than food supply, resulting inevitably in widespread famine, disease, and war

Population is geometric (2, 4, 8, 16…)Food supply is arithmetic (1, 2, 3, 4…)

– Malthus predicted a global population maximum of 4 billion people

Malthusian Checks –

Checks keep a population in line with the food supply.

Positive Checks:

• Higher Death Rates:– Disease – Pestilence/Epidemic– War– Famine

Preventative Checks:

Lower Birth Rates:– Postponement of Marriage– Consumerism– Education– Minimum Wage

What Did He Mean?

His theory maintained that population always had a tendency to push above the food supply, and that increasing the food supply or the level of incomes of the poor was pointless as they would simply have even more kidsMaintained that crisis brought on by population would be felt unevenly – the poor will be most greatly affected

Do we see this trend in lower/less developed countries?