4.2 Demographic transition

The sex ratio is the number of males per 100 females in a population: l Male births consistently exceed female births due to a combination of biological and social reasons. l After birth, the gap generally begins to narrow until eventually females outnumber males, as at every age male mortality is higher than female mortality. l A report published in China in 2002 recorded 116 male births for every 100 female births due to the significant number of female fetuses aborted by parents intent on having a male child.

Dependants are people who are too young or too old to work. The dependency ratio is the relationship between the working or economically active population and the non-working population. A dependency ratio of 60 means that for every 100 people in the economically active population there are 60 people dependent on them. The dependency ratio in developed countries is usually between 50 and 75 with the elderly forming an increasingly high proportion of dependants. In contrast, developing countries typically have higher dependency ratios, which may reach over 100. Here young people make up the majority of dependants. The dependency ratio is important because the economically active population will in general contribute more to the economy. In contrast, the dependent population tend to be bigger recipients of government funding, particularly for education, health care and public pensions.

Dependency ratio is the ratio of the number of people under 15 and over 64 years to those aged 15–64. number aged 0–14 + number aged over 64 number aged 15–64 Elderly dependency ratio is the ratio of the number of people aged 65 and over to those 15–64 years of age. number aged over 64 number aged 15–64) Youth dependency ratio is the ratio of the number of people aged 0–14 to those 15–64 years of age. number aged 0–14 number aged 15–64 × 100 × 100 × 100

5 Define infant mortality rate. 6 Briefly describe the contrast in the causes of death between more developed and less developed countries. 7 What do you understand by the terms (a) population structure and (b) population pyramid? 8 What does a dependency ratio of 80 mean? 9 How does the structure of dependency vary between developed and developing countries?

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Although the birth and death rates of no two countries have changed in exactly the same way, some broad generalisations can be made about population change that are illustrated by the model of demographic transition (Figure 4.4).

Revised

Demographic transition is the historical shift of birth and death rates from high to low levels in a population.

Stages 1

High stationary 40 Births and deaths per 1000 per year 30 20 10 0 Birth rate

Death rate

Population growth

Figure 4.4 Model of demographic transition

5 Natural decr ease

l No country as a whole retains the characteristics of stage 1, which applies only to the most remote societies on Earth. l The poorest of the developing countries are in stage 2. l Most developing countries that have registered significant social and economic advances are in stage 3. l All the developed countries of the world are now in stages 4 or 5.

The basic characteristics of each stage are as follows:

Stage 1 The crude birth rate is high and stable while the crude death rate is high and fluctuating due to the sporadic incidence of famine, disease and war. Population growth is very slow and there may be periods of considerable decline. Infant mortality is high and life expectancy low.

Stage 2 The death rate declines significantly. The birth rate remains high as the social norms governing fertility take time to change. The rate of natural change increases to a peak at the end of this stage. Infant mortality falls and life expectancy increases. The reasons for the decline in mortality are: better nutrition; improved public health, particularly in terms of clean water supply and efficient sewerage systems; and medical advances.

Stage 3 Social norms adjust to the lower level of mortality and the birth rate begins to decline. Life expectancy continues to increase and infant mortality to decrease.

Stage 4 Both birth and death rates are low. The former is generally slightly higher, fluctuating somewhat due to changing economic conditions. Population growth is slow. Death rates rise slightly as the average age of the population increases. However, life expectancy still improves as age-specific mortality rates continue to fall.

Stage 5 The birth rate has fallen below the death rate, resulting in natural decrease. In the absence of net migration inflows these populations are declining.

Criticisms of the model: l It is seen as too Eurocentric as it was based on the experience of Western

Europe. l Many developing countries may not follow the sequence set out in the model. l It fails to take into account changes due to migration.

It is very important to be clear where the boundary lines are between each stage of the demographic transition model and to understand why they are in those particular places.

Compared with the experiences of most developed nations before them, in the developing world: l birth rates in stages 1 and 2 were generally higher l the death rate fell much more steeply and for different reasons l some countries had much larger base populations and thus the impact of high growth in stage 2 and the early part of stage 3 has been far greater l for those countries in stage 3 the fall in fertility has also been steeper

10 Define demographic transition. 11 List the reasons for declining mortality in stage 2. 12 What happens in stage 5? 13 State two criticisms of the model of demographic transition.

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The world’s population is ageing significantly. The global average for life expectancy increased from 46 years in 1950 to nearly 65 in 2000. It is projected to reach 74 years by 2050. Europe is the ‘oldest’ region in the world. Those aged 60 years and over currently form 20% of the population. Africa is the ‘youngest’ region in the world, with the proportion of children accounting for 43% of the population today.

The problem of demographic ageing has been a concern of developed countries for some time, but it is now also beginning to alarm developing nations. Demographic ageing will put health-care systems, public pensions, and government budgets in general, under increasing pressure. In many developed countries the fastest-growing segment of the population is the so-called ‘oldestold’ (85 years or more). It is this age group that is most likely to need expensive residential care. Japan has the most rapidly ageing population in history. It has the highest life expectancy in the world and one in five of the population is over the age of 60. No other country has a lower percentage of its population under 15. Younger workers are at a premium and there is considerable competition to recruit them.

Revised

An ageing population is one undergoing a rise in its median age. It occurs when fertility declines, while life expectancy remains constant or increases.

Development involves improvement in the quality of life. This includes wealth, but it also refers to other important aspects of our lives, such as education, health and freedom of expression. For example, development occurs in a lowincome country when: l local food supply improves due to investment in machinery and fertilisers l the electricity grid extends outwards from the main urban areas to rural areas

The highest-ranking countries according to the human development index are in stage 4 (or stage 5) of demographic transition, suggesting a very strong link between the rate of population growth and the level of economic development. The countries with low human development invariably have high rates of population growth and most are in stage 2 of demographic transition. The more advanced developing countries are generally in stage 3 of demographic transition. This includes countries such as Brazil, Mexico, India and Malaysia. However, the development process is complex and is the result of the interaction of a wide range of factors.

Figure 4.5 illustrates changes in birth and death rates in England and Wales between 1700 and 2000. The birth and death rates in stages 1, 2 and 3 broadly

Revised

Development is the use of resources to improve the quality of life in a country.

You should be able to differentiate between economic growth and development. The former is an increase in GDP while the latter is a much more wide ranging concept concerning many more aspects of quality of life, such as education and health.

The human development index is a measure of development that combines three important aspects of human wellbeing: life expectancy, education and income.

correspond to those in many poorer societies today. The graph identifies a range of important factors that influenced birth and death rates in England and Wales during the time period concerned.

Source: Advanced Geography: Concepts & Cases by P. Guinness & G. Nagle (Hodder Education, 1999), p. 4 1833 Factories ban child labour 1834 Poor Law amendment Act 1874 Compulsory registration Birth rate Death rate 1874 Compulsory registration First World War: drop in births Post-war baby boom Short period of natural decrease 1911 National insurance against sickness 1875 Public Health Act (established local sanitary districts) 1876 Rv. Bradlaugh spread birth control propaganda: size of families deliberately restricted 1801 First census

1798 Jenner discovered vaccination against smallpox 1868 Local authorities condemn unfit buildings 1921 Local councils treat TB This rise was most marked among infants and in large towns: due to food shortage, bad housing and sanitary conditions Decline in death rate: advances in medical science, improved sanitary conditions, greater food supply as result of agrarian reform

Period of cheap gin drinking 1836 Voluntary registration of births and deaths Voluntary hospitals founded Dispensary movement began. Outpatients treated at hospitals 1700 0 15 20 25 30 35 40 1720 1740 1760 1780 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 1848 Public Health Act (established boards of health for pure water supply and drainage)

Figure 4.5 England and Wales: changes in birth and death rates, 1700–2000

Child mortality has been falling significantly. Globally, the number of children under 5 years who died in 2006 dropped below 10 million for the first time, down from almost 13 million in 1990. The main reasons for the decline included measles vaccinations, mosquito nets and increased rates of breast-feeding. Unicef argues that the majority of the remaining child deaths are preventable. Reducing maternal mortality is one of the UN’s eight Millennium Development Goals. There is a huge contrast in maternal mortality between the developed and developing worlds. Globally, 1 in 92 women die from pregnancy-related causes. However, in more developed nations the risk is only 1 in 6000 compared with 1 in 22 in sub-Saharan Africa. Major influencing factors in maternal mortality are the type of pre-natal care and the type of attendance at birth. On a global scale 75% of the total improvement in longevity has been achieved in the twentieth century and the early years of the twenty-first century. In 1900 the world average for life expectancy is estimated to have been about 30 years, but by 1950–55 it had risen to 46 years. The current global average is 68 years.

Students sometimes confuse child mortality and infant mortality. The former refers to children under the age of 5, the latter to children under the age of 1.

Child mortality rate is the number of children who die before their 5th birthday per 1000 live births. Maternal mortality is the death of a woman during or shortly after a pregnancy.

14 By how much has global average life expectancy increased since 1950? 15 Which two factors have resulted in such an elderly population in Japan? 16 Which three quality-of-life indicators are used in the human development index? 17 Define child mortality. 18 By how much did child mortality decrease between 1990 and 2006?

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