Human Demographics

IntroductionDemographics is the study

of human populations.These studies involve data

collection, statistical analysis and mathematical modeling to interpret and predict the patterns of human population growth, population density and the distribution of humans and the resources they need across the globe.

World DemographicsSince the Industrial

Revolution, birth rates have been fairly stable at 25-30 births per 1000 people per year.

However the death rates have dropped dramatically from between 25-30 deaths per 1000 down to 13 deaths per 1000 people per year.

Therefore the world population is increasing by 12-17 per 1000 people per year!

World DemographicsThe growth rate is

not uniform.Developing nations

are growing much faster than industrial nations.

Why?

World DemographicsThe biggest reason is the difference in age

structure in developing nations.Developing nations have more individuals in their

reproductive or pre-reproductive years than in their post reproductive years.

These countries have what is known as a growth momentum, which is the expected future growth of a population due to a disproportionate amount of younger individuals.

Industrialized nations either have more individuals in their post reproductive years or similar numbers of individuals in all age categories.

Population PyramidsAge structure is usually conveyed in population

pyramids.

Population Pyramids

Births and DeathsUsually the main

influences on population growth are birth rates and infant mortality.

Death of post-reproductive individuals does nothing to influence population growth.

Overall, infant mortality has decreased in all human populations.

Births and DeathsIn some countries,

birth rates have declined.

These countries are usually ones that have better opportunities for women.

As women go to school, work and have improved health care, the time to have a large family has decreased.

Demographic Transition ModelAn American demographer, Warren Thompson,

formulated the demographic transition model to show the correlation between changes in population size and economic development/increased standard of living.

Demographic Transition ModelAccording to the model, as a population

becomes more industrialized, its population growth rate will decrease.

Some post-industrial countries actually have negative growth rates as their populations are declining.

Demographic Transition ModelDue to Canada having distinct populations of

people living in different socio-economic and geographic locations, it is in different stages of the demographic transition model (DTM) in different areas of the country.

Southern Canada is in the industrial stage of the DTM. It has a very small population growth.

Nunavut, is in the pre-industrial stage based on their population age-structure. They have a higher growth momentum than Southern Canada with 33 births per 1000 people compared to 11 births per 1000 people.

Cultural factors and quality of life do come into play.

Gross National Product (GNP)The gross national product (GNP) is used as a

measure of a country’s level of industrialization.The higher a country’s GNP, the longer the life

expectancy, the lower the infant mortality, but the slower the population is growing.

USA Brazil Ethiopia

Fertility Rate 2.1 3.0 6.9

Infant Mortality Rate

8.3 66 110

Life Expectancy (years)

76 57 52

Doubling Time (years)

98 40 22

GNP ($) 23,120 2770 110

Future Trends???Will our world survive the 21st century?Demographers have been trying to predict the future

trends of the human population since Thomas Malthus published his famous book “An Essay on the Principle of Population” in which he predicted massive starvation due to the geometric growth of resources and the exponential growth of humans in the 18th century.

Paul Ehrlich, a biology professor at Stanford, wrote “The Population Bomb” in 1968 in which he predicted massive starvation as he felt the world’s water and food resources were at their limits.

In 1990 he wrote the sequel, “The Population Explosion”, in which he states the world is living in an unsustainable manner that stretches the limits of the Earth supporting life.

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