THE DEMOGRAPHIC TRANSITION MODEL€¦ · What are the stages of the Demographic Transition Model? In Stage 3, birth rates gradually decrease, usually as a result of improved economic

THE DEMOGRAPHIC TRANSITION MODEL

What are the stages of the Demographic Transition Model?

In Stage 1, which applied to most of the world before the Industrial Revolution, both birth rates and death rates are high. As a result, population size remains fairly constant but can have major swings with events such as famines, wars or pandemics which can kill large numbers of people.

What are the stages of the Demographic Transition Model?

In Stage 2, better medical care, improved diet and better public sanitation lowers death rates, especially among children, while birth rates remain high; the result is rapid population growth. Many of the least developed countries today are in Stage 2.

What are the stages of the Demographic Transition Model?

In Stage 3, birth rates gradually decrease, usually as a result of improved economic conditions, an increase in women’s status, and access to contraception. Population growth continues, but at a lower rate. Most developing countries are in Stage 3.

What are the stages of the Demographic Transition Model?

In Stage 4, birth and death rates are both low, stabilizing the population. These countries tend to have stronger economies, higher levels of education, better healthcare, a higher proportion of working women, and a fertility rate hovering around two children per woman. There are many elderly people and the dependency ratio is high as working people support elderly relatives. Government spending on health-care and pensions increases. Most developed countries are in Stage 4.

A possible Stage 5 would include countries in which fertility rates have fallen significantly below replacement level (2 children) and the elderly population is greater than the youthful population.

Demographic Transition

Demographic Transition Model

The Dependency Ratio• Dependents: those persons under 15 and over 65 years of age

• Economically productive: those between the ages of 15-65

• Dependency Ratio:

Number employed

Total Population MINUS Number employed

Population = 1,100,000

Employed = 100,000

Dependency Ratio:

100,000 OR 100,000 = 1:10

» 1,100,000 – 100,000 1,000,000

How can a high dependency ratio affect the economic

development of a country?

Ways a high dependency ratio can affect the economic development of a country:

1. Insufficient funds from taxation so insufficient funds to provide employment

2. Poverty: malnutrition/ inadequate food supply (low levels of productivity)

3. Inadequate health facilities (low productivity)4. Lack of education for all (high illiteracy rates

leading to shortage of human resources/skilled manpower)

5. Inadequate housing 6. Poor sanitation7. High crime rate (affects businesses and

discourages foreign investment)

Population Changes:-• An increase is called Population Growth.• Population growth is affected by:

– Natural increase (the increase in population brought about when the birth rate exceeds the death rate)

– Net migration (inward and outward migration)

• Birth rate (no. of live births per 1000 persons in the population in a given year)

• Death rate (no. of deaths per 1000 persons in the population in a given year)

• Migration rate (migration per 1000 persons in the population in a given year)

• Changes in the structure of the population (age, sex etc) will affect the economic development of a country.

Jamaica’s Population 1911-1991

YEAR POPULATION SIZE (‘000s)

1911 831

1921 858

1943 1237

1960 1610

1970 1814

1982 2190

1991 2381

2001 2700

1. Between 1911 and 2001 the population of Jamaica increased by ____ thousands.

2. The period between ______ and _____ was the period of greatest increase.

3. The period between 1911 and 1921 showed an increase of _____ thousand.

4. The rate of increase for the period 1911 to 1921 was ______ percent.

5. The rate of increase for the period 1991 to 2001 was ______ percent.

Trinidad and Tobago• Population growth rate: -0.17% (2016 est.)

• Definition: The average annual percent change in the population, resulting from a surplus (or deficit) of births over deaths and the balance of migrants entering and leaving a country. The rate may be positive or negative. The growth rate is a factor in determining how great a burden would be imposed on a country by the changing needs of its people for infrastructure (e.g., schools, hospitals, housing, roads), resources (e.g., food, water, electricity), and jobs.

• Rapid population growth can be seen as threatening by neighbouring countries.

• Population size varies from country to country and there is a direct relationship between the population size and the economic development of a country.

Area and population size - 1997COUNTRY AREA (KM SQ) POPULATION (000s)

Barbados 431 264

Belize 22960 217

Guyana 214799 800

Jamaica 11424 2500

Trinidad and Tobago

5128 1300

1. The country with the largest population is Jamaica. T/F2. The country with the smallest population is Barbados. T/F3. The country with the smallest area is Barbados. T/F4. The country with the largest area is Belize. T/F5. The country with the largest land area has the smallest population. T/F

POPULATION DENSITY

POPULATION DENSITY• The number of persons per unit area of a country

or region

• Formula for calculating:-

TOTAL POPULATION

AREA

Population of Country X = 217000

Area of Country X = 22960 km2

Population Density = 217000

22960 = 9 persons per km2

Calculate the population densities:Country Area(km2) Population

(000s)Density

Barbados 431 264

Belize 22960 217

Guyana 214799 800

Jamaica 11424 2500

Trinidad and Tobago

5128 1300

Calculate the population densities:Country Area(km2) Population

(000s)Density

Barbados 431 264 612 per km2

Belize 22960 217 9 per km2

Guyana 214799 800 4 per km2

Jamaica 11424 2500 219 per km2

Trinidad and Tobago

5128 1300 254 per km2

Factors affecting density are:1. Relief of the land

– Prefer flat or undulating land to land that is mountainous, swampy, etc.

2. Climate– hospitable or inhospitable

o Very heavy rainfallo Very low temperatureso Long periods of droughto Caribbean cities located on leeward side of the islands

(less rainfall and less forested)

3. Fertile areas4. Location of Mineral resources (industries – jobs)5. Availability of infrastructure

– roads, electricity, water, schools, health facilities, postal service, police station etc - Developed areas

6. Type of vegetation – People avoid heavily forested areas, desert areas etc

Population Growth

Growth in world population:

8000 BC: 5 million

0 AD: 300 million

1800 AD: 1 billion

1900 AD: 1.2 billion

1960 AD: 3 billion

2000 AD: 5 billion

2011 AD: 7 billion

• Decrease in death rate (no. of deaths out of each 1000 persons in a country) and increase in birth rate (no. of live births each year per 1000 persons in the country)

• Growth rate is found by finding the difference between the birth rate and the death rate. It can be positive or negative.

• Natural increase: term used when births exceed deaths

Calculating Natural Increase: Birth and Death rates for Some Caribbean Countries (1996)

Country Birth rate

/1000

Death rate

/1000

Natural increase

/1000

Trinidad & Tobago 18 6 12

Barbados 15 9 ?

Belize ? 5 29

Dominica 15 ? 8

Grenada 31 7 ?

Line graph showing the natural increase for T&T 1990-2005

0

5

10

15

20

25

1990 1992 1995 1997 2000 2002 2005

Bir

th/d

eat

h r

ate

Year

Natural increase

crude birth rate

crude death rate

What factors affect the birth rate?

Birth rates are affected by:

1. The number of women of child-bearing age

2. Norms within a society for family size

3. The economic conditions of a country

4. The educational level of the population

5. Availability and acceptance of family planning methods

6. Government policy towards population control

Birth rates are highest in low-income countries.

The Fertility Rate

• The average number of children that a woman in a given population is expected to give birth to in her lifetime.

• If greater than 2.0 it leads to a growing population.

• If close to 2.0 population numbers are steady.

• If less than 2.0 it results in a declining population.

What factors affect the death rate?

Factors influencing the death rate

1. Medical facilities/health care(proper health care lowers the death rate)

2. Nutritional levels(better nutrition, lower death rate)

3. Economic prosperity/ level of development(people in developed countries live longer)

4. Population structure (many elderly = high death rate)

What is the Infant Mortality Rate?

Infant Mortality: the number of deaths of infants under one year old per 1,000 live births.

This rate is often used as an indicator of the level of health in a country. The infant mortality rate of the world is 49.4 according to the United Nations and 42.09 according to the CIA World Factbook.

Draw a line graph to show infant mortality

Year Jamaica Barbados

1955 91.9 84.1

1965 61.4 45.4

1975 45.0 31.4

1985 35.8 21.0

1995 28.8 16.0

2000 26.8 14.3

2005 24.4 13.7

What is Life Expectancy?

Life Expectancy: the average number of years that persons in a given population are expected to live

• When the resources of a country are not sufficient to provide for the needs of the population, that country is OVERPOPULATED.

• When the amounts of resources available in a country can support a larger population, it is considered to be UNDER POPULATED

• The OPTIMUM POPULATION is that in which the number of persons in a country will make efficient use of the available resources