1. Population change 2 The Demographic Transition Model

2. 1.1 What is demographic change?
• The net change in the population store caused by the inputs of births and in-migration and the outputs of death and out-migration.
• Global population growth, totals, distribution and density.
1.2. How and why do populations change naturally?
• A study of countries at Stages 2-5 of the demographic transition to demonstrate variations in fertility and mortality rates, including infant mortality and life expectancy.
1.3 What is the role of migration in population change?
• Characteristics of different types of migration.
• The economic, social and environmental impacts of migration on exporting and receiving countries/regions.
1.4 What are the issues of the migration of refugees and asylum seekers?
• The causes and consequences of flows of refugees and asylum seekers into developed economies both from a historical and current dimension.
• Housing.
• Repatriation.
• The attitudes and values of migrants and hosts.
• Human rights.

3. 1.5 What are the causes and impacts of changing gender structures?
• Changing gender structures in populations as countries pass through the demographic transition.
• Social, economic and political impacts of gender structures.
1.6 What are the demographic challenges facing countries?
• The demographic causes and effects of ageing societies including issues such as dependency, workforce and pensions.
• The issues of high birth rates and high mortality rates
– including AIDS.
• Policies to alleviate the ‘demographic challenges’

6. Demographic Transition Model
Stage 1
Stage 2
Stage 3
Stage 4
Total
Population
Natural
Increase
In Population
Natural
Decrease
In Population
Birth Rate
Death Rate

8. Stage 1 High Fluctuating
Low population
Increasing very slowly
High birth rate
High death rate
Ethiopia/Niger
UK: pre-1780
Birth Rate
Death Rate
Total
Population

9. Stage 2 Early Expanding Population growing at faster rate
High but decreasing birth rate
Decreasing death rate
Sri Lanka/Bolivia
UK:
Birth Rate
Death Rate
Total
Population

10. Stage 3 Late Expanding
Stage 3
Population still increasing, but rate of increase slowing down
Decreasing birth rate
Low death rate
Uruguay/China
UK:
Total
Population
Birth Rate
Death Rate

11. Stage 4 Low Fluctuating High population, almost stable Low birth rate
Low death rate
Canada/USA
UK: post-1940
Total
Population
Birth Rate
Death Rate

12. Demographic Transition Model
Stage 1
Stage 2
Stage 3
Stage 4
Total
Population
Natural
Increase
In Population
Natural
Decrease
In Population
Birth Rate
Death Rate
Ethiopia/
Niger
UK:
pre-1780
Sri Lanka/
Bolivia
UK:
Uruguay/
China
UK:
Canada/
USA
UK:
Post-1940

13. What do you think the reasons are for the changes at each stage?

14. Reasons for Stage 1 High Fluctuating
Little access to birth control
Many children die in infancy so parents have more to compensate
Children are needed to work on the land
Some religions encourage large families
Death rates are high due to disease, famine, poor diet, poor hygiene, little medical science
Birth Rate
Death Rate
Total
Population

15. Reasons for Stage 2 Early Expanding
Improvements in medical care
Improvements in sanitation and water supply
Quality and quantity of food produced improves
Transport and communications improve movements of food and medical supplies
Decrease in infant mortality
Birth Rate
Death Rate
Total
Population

16. Reasons for Stage 3 Late Expanding
Increased access to contraception
Lower infant mortality rates so less need for bigger families
Industrialisation and mechanisation means fewer labourers required
As wealth increases, desire for material possessions takes over the desire for large families
Equality of women means they can follow a career rather than just staying at home
Stage 3
Total
Population
Birth Rate
Death Rate

17. Reasons for Stage 4 Low Fluctuating
Rates fluctuate with ‘baby booms’ and epidemics of illnesses and diseases
Reasons for Stage 4 have improved and it stabilises
Total
Population
Birth Rate
Death Rate

18. Stage 5: Depleting Population
Is there a Stage 5? ? ? ?
Stage 5: Depleting Population

19. Problems What problems do you think there could be with the model?
It does not include the influences of migration
It assumes that all countries will go through the same pattern
There is no time scale
Reasons for birth rates and death rates are very different in different countries
And finally, is there a stage 5?

20. LIMITATIONS OF THE DEMOGRAPHIC TRANSITION MODEL
As a descriptive model the DMT seems to fit the experience of a number of countries very well, e.g. the UK and Sweden as shown in slides 4 and 5.
The change in birth and death rates over time can be plotted over time by means of a graph as shown at left. As can be seen different countries have taken different shaped paths to achieve Stage 4.

21. When Notestein developed the DMT in 1945, his model postulated that as economic development progresses death rates will decline, followed by birth rates, as happened in Western countries. But will developing countries with different cultural and economic experiences follow the same path.
Some countries seem to have low GNP per capita (wealth) but lower than expected birth rates, and others high GNP per capita and higher than expected birth rates. Here are some reasons will help to explain these.
* government supported family planning policies
* state controlled economy (communist regime)
* sudden wealth (oil rich economy
* Muslim cultural values
The DMT’s emphasis on economic forces means that cultural factors on population change have been neglected, and this is a serious shortcoming.

22. Rapid Growth

23. Slow Growth

24. Negative Growth

25. The End?

26. 1. ADD KEY WORDS: HIGH, LOW, STATIONARY, FALLING, RISING, EXPANDING SLOWLY, EXPANDING QUICKLY
2. DRAW A LINE TO SHOW THE CHANGE IN THE TOTAL POPULATION

29. Birth and Death Rates, Worldwide
Rates of birth, death, and natural increase per 1,000 population
Natural Increase
Birth rates and death rates are declining around the world. Overall economic development, public health programs, and improvements in food production and distribution, water, and sanitation have led to dramatic declines in death rates. And women now have fewer children than they did in the 1950s.
Nevertheless, if death rates are lower than birth rates, populations will still grow.
Also, it is possible for absolute numbers of births to increase even when birth rates decline.
Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

30. Notes on Birth and Death Rates, Worldwide
Birth rates and death rates are declining around the world. Overall economic development, public health programs, and improvements in food production and distribution, water, and sanitation have led to dramatic declines in death rates. And women now have fewer children than they did in the 1950s.
Nevertheless, if death rates are lower than birth rates, populations will still grow.
Also, it is possible for absolute numbers of births to increase even when birth rates decline.

31. 10 Places With the Lowest Total Fertility Worldwide
Average number of children per woman,
Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

32. Women of Childbearing Age
Number of Women 15 to 49
Billions
The number of women of childbearing age more than doubled between 1950 and 1990: from 620 million to over 1.3 billion.
Their numbers are expected to reach over 2 billion by the middle of this century, according to the UN’s medium projections.
The growing population of women in their childbearing years and their male partners will contribute to future world population growth, even if levels of childbearing continue to decline.
Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

33. Notes on Women of Childbearing Age
The number of women of childbearing age more than doubled between 1950 and 1990: from 620 million to over 1.3 billion.
Their numbers are expected to reach over 2 billion by the middle of this century, according to the UN’s medium projections.
The growing population of women in their childbearing years and their male partners will contribute to future world population growth, even if levels of childbearing continue to decline.

34. Women of Childbearing Age and Fertility
Worldwide
The number of women in their childbearing years has increased since the 1950s and is projected to continue to increase to 2050.
The number of children per woman has declined since the 1950s and is projected to continue to decline.
Even though women have on average fewer children than their mothers, the absolute number of babies being born continues to increase because of the increases in the total number of women of childbearing age.
Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

35. Notes on Women of Childbearing Age and Fertility
The number of women in their childbearing years has increased since the 1950s and is projected to continue to increase to 2050.
The number of children per woman has declined since the 1950s and is projected to continue to decline.
Even though women have on average fewer children than their mothers, the absolute number of babies being born continues to increase because of the increases in the total number of women of childbearing age.

36. Population in Countries With Low Fertility
Decline or Growth,
Percent
Country (average number of children per woman)
Thailand (1.7)
China (1.6)
Armenia (1.3)
Trinidad & Tobago (1.6)
All countries shown here have below “replacement level” childbearing —the level required for population to ultimately stop growing or declining. Yet, half will continue to grow and half are projected to decline by 2050.
This disparity is due to the effects of population momentum. In populations with a young age structure, even if fertility declines sharply, the numbers of children will continue to increase for a generation as the cohorts of young people pass through their reproductive years. Consequently, populations will continue to grow for decades even if fertility is instantly reduced to replacement level. On the other hand, some low-fertility countries are subject to negative population momentum. Their populations have aged enough to result in relatively small cohorts under age 30, and therefore even if fertility were to rise to replacement level, population size would decline for sometime.
Italy (1.3)
Russia (1.4)
Source: Population Reference Bureau, 2005 World Population Data Sheet.

37. Notes on Population in Countries With Low Fertility
All countries shown here have below “replacement level” childbearing—the level required for population to ultimately stop growing or declining. Yet, half will continue to grow and half are projected to decline by 2050.
This disparity is due to the effects of population momentum. In populations with a young age structure, even if fertility declines sharply, the numbers of children will continue to increase for a generation as the cohorts of young people pass through their reproductive years. Consequently, populations will continue to grow for decades even if fertility is instantly reduced to replacement level. On the other hand, some low-fertility countries are subject to negative population momentum. Their populations have aged enough to result in relatively small cohorts under age 30, and therefore even if fertility were to rise to replacement level, population size would decline for sometime.

38. Diverging Trends in Fertility Reduction
Average number of children per woman
Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

39. Patterns of Fertility Decline
Average number of children per woman
Uganda
Kenya
Colombia
South Korea
Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

40. Reaching Replacement Fertility
Average number of children per woman
Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

41. Trends in Urbanization, by Region
Urban Population
Percent
Currently, world regions differ greatly in their levels of urbanization. In more developed regions and in Latin America and the Caribbean, over 70 percent of the population is urban, whereas in Africa and Asia, under 40 percent of the population is urban. By 2030, however, the urban proportion of these two regions will exceed 50 percent.
By 2030, roughly 60 percent of the world’s population will be living in urban areas.
Source: United Nations, World Urbanization Prospects: The 2003 Revision (medium scenario), 2004.

42. Notes on Trends in Urbanization, by Region
Currently, world regions differ greatly in their levels of urbanization. In more developed regions and in Latin America and the Caribbean, over 70 percent of the population is urban, whereas in Africa and Asia, under 40 percent of the population is urban. By 2030, however, the urban proportion of these two regions will exceed 50 percent.
By 2030, roughly 60 percent of the world’s population will be living in urban areas.

43. Largest Cities, Worldwide
Millions
The largest cities in the world are growing rapidly in size and they are shifting from the more developed regions to the less developed regions. In 1950 the three largest cities were in more developed countries; by 2000, only Tokyo remained in the top three.
In 1950, New York was the largest city in the world, with a population of about 12 million. By 2015, the largest city worldwide is projected to be Tokyo, with triple this population size: 36 million.
Source: United Nations, World Urbanization Prospects: The 2003 Revision (medium scenario), 2004.

44. Notes on Largest Cities, Worldwide
The largest cities in the world are growing rapidly, and they are shifting from the more developed regions to the less developed regions. In 1950 the three largest cities were in more developed countries; by 2000, only Tokyo remained in the top three.
In 1950, New York was the largest city in the world, with a population of about 12 million. By 2015, the largest city worldwide is projected to be Tokyo, with triple this population size: 36 million.

45. Urbanization in Central America
Population Living in Urban Areas
Percent
Central American countries are urbanizing rapidly, at a pace similar to that of their South American neighbors 20 years earlier. Sixty percent or more of the population in Costa Rica, El Salvador, Nicaragua, and Panama is projected to be urban by 2010; the projection for Central America as a whole is 71 percent.
South America has nearly the highest rate of urbanization of any world region, projected to achieve 84 percent by 2010 (virtually tied with Northern Europe).
Source: United Nations, World Urbanization Prospects: The 2003 Revision (medium scenario), 2004.

46. Notes on Urbanization in Central America
Central American countries are urbanizing rapidly, at a pace similar to that of their South American neighbors 20 years earlier. Sixty percent or more of the population in Costa Rica, El Salvador, Nicaragua, and Panama is projected to be urban by 2010; the projection for Central America as a whole is 71 percent.
South America has nearly the highest rate of urbanization of any world region, projected to achieve 84 percent by 2010 (virtually tied with Northern Europe).

47. Age Distribution of the World’s Population
Population Structures by Age and Sex, 2005
Millions
Less Developed Regions
More Developed Regions
Age
0-4
Male
Female
Male
Female
Sex and age distributions show that less developed countries have significantly younger populations than more developed countries.
Almost one-third of the population in less developed countries is under age 15. In contrast, less than one-fifth of the population in more developed countries is under 15.
Today there are more than 2 billion young people below age 20 in less developed regions—the age cohort that will soon become the world’s newest group of parents.
Young age structures in the less developed countries are due mainly to higher levels of childbearing in recent decades.
Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

48. Notes on Age Distribution of the World’s Population
Sex and age distributions show that less developed countries have significantly younger populations than more developed countries.
Almost one-third of the population in less developed countries is under age 15. In contrast, less than one-fifth of the population in more developed countries is under 15.
Today there are more than 2 billion young people below age 20 in less developed regions—the age cohort that will soon become the world’s newest group of parents.
Young age structures in the less developed countries are due mainly to higher levels of childbearing in recent decades.

49. Trends in Aging, by World Region
Population Ages 65 and Older
Percent
By 2025, over 20 percent of the population in more developed regions will be ages 65 and older.
By 2025, one-tenth of the world’s population will be over age 65.
Asia will see the proportion of its elderly population almost double, from about 6 percent in 2000 to 10 percent in In absolute terms, this represents a stark increase in just 25 years: from about 216 million to about 480 million older people.
Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

50. Notes on Trends in Aging, by World Region
• By 2025, over 20 percent of the population in more developed regions will be ages 65 and older.
• By 2025, one-tenth of the world’s population will be over age 65.
• Asia will see the proportion of its elderly population almost double, from about 6 percent in 2000 to 10 percent in In absolute terms, this represents a stark increase in just 25 years: from about 216 million to about 480 million older people.

51. Women and Aging
Projected World Population, by Sex, at Specified Age Groups, 2025
Percent
The figure above depicts what demographers refer to as the feminization of aging. Although women make up half of world population, by the end of the next quarter century, they will account for more than half (54 percent) of people ages 60 and older, and 63 percent of very old people (80 and older).
Source: United Nations, World Population Prospects:The 2004 Revision (medium scenario), 2005.

52. Notes on Women and Aging
• The figure above depicts what demographers refer to as the feminization of aging. Although women make up half of world population, by the end of the next quarter century, they will account for more than half (54 percent) of people ages 60 and older, and 63 percent of very old people (80 and older).

53. Adult Literacy, by Region
Literacy Rates, by Sex,
Percent
Nearly all men and women in more developed regions can read and write.
However, literacy rates are lower in the less developed regions. Women’s literacy rates in particular vary significantly by region: from 53 percent in sub-Saharan Africa, to 73 percent in Asia, to 89 percent in Latin America and the Caribbean.
Overall, more men than women are literate. This is especially striking in the Arab states, where more than three-fourths of men but about half of all women are literate.
Source: UNESCO Institute for Statistics: accessed online at on May 21, 2006.

54. Notes on Adult Literacy, by Region
Nearly all men and women in more developed regions can read and write.
However, literacy rates are lower in the less developed regions. Women’s literacy rates in particular vary significantly by region: from 53 percent in sub-Saharan Africa, to 73 percent in Asia, to 89 percent in Latin America and the Caribbean.
Overall, more men than women are literate. This is especially striking in the Arab states, where more than three-fourths of men but about half of all women are literate.

55. Ratio of Workers to Dependents, by Region
Note: People 15 to 64 are considered to be workers; people 14 and younger and those over 65 are considered to be dependents.
Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

56. Availability of Doctors, Selected Countries*
Physicians per 1,000 people
Population growth can affect a country’s capacity to address the health needs of its people through trained personnel and accessible health facilities.
Access to health services varies greatly from country to country. In Greece, for example, there are 4.4 doctors for every 1,000 people.
This is over 20 times higher than in Cambodia, which has only 0.2 doctors for every 1,000 people.
* Data are for the most recent year available for each country.
Source: World Bank, World Development Indicators 2006.

57. Notes on Availability of Doctors, Selected Countries
Population growth can affect a country’s capacity to address the health needs of its people through trained personnel and accessible health facilities.
Access to health services varies greatly from country to country. In Greece, for example, there are 4.4 doctors for every 1,000 people.
This is over 20 times higher than in Cambodia, which has only 0.2 doctors for every 1,000 people.