1.2 Changing population and places Flashcards
Define demography
The study of population dynamics and changes.
Key demographic terms
-Crude birth rate (CBR)
-Crude death rate (CDR)
-Natural increase (NI)
-Life expectancy
-Fertility rate
-Infant mortality rate
Define crude birth rate (CBR)
The number of live births per 1,000 people per year in a region.
Spacial and temporal variations in crude birth rate (CBR)
-In pre-industrial societies, the rate is around 45/1,000/year: today, only a few remaining isolated rainforest tribes have a CBR close to this figure.
-The European average is 11/1,000/year.
-The CBR becomes lower not only on account of falling fertility but also due to increasing life expectancy (which means a higher proportion of each 1,000 people are not of child-bearing age).
Define crude death rate (CDR)
The number of deaths per 1,000 people per year in a region (a measure of mortality).
Spacial and temporal variations in crude death rate (CDR)
-In pre-industrial societies, the rate is 40–50/1,000/year.
-Today, the European average is 10/1,000/year.
-The CDR can increase due to disasters or disease: in Haiti, in 2010, it rose from 8 to 32/1,000/year on account of a large earthquake.
Define natural increase (NI)
-The difference between the CBR and CDR.
-It can be recorded either as the net change per 1,000 people or as a percentage.
Spacial and temporal variations in natural increase (NI)
-It is rare for a country’s rate of NI to exceed 3 per cent per annum.
-Youthful migrant populations, such as those found in developing world megacities, have a high rate of NI due to the presence of a large proportion of fertile adults and relatively fewer older people.
Define life expectancy
The average number of years a member of a particular society can expect to live.
Spacial and temporal variations in life expectancy
-The average world life expectancy is now 71 (in 1960 it was 52).
-In most of Latin America and Asia, the figure is 70 years or higher.
-In 2015, the world’s lowest was 49 in Swaziland; the highest was 84 in Japan (South Korea is predicted to overtake Japan soon, however).
-In most countries, national averages obscure a difference between men and women of around six years (Japan’s female life expectancy is 87; for men it is 81).
Define fertility rate
The average number of children a woman gives birth to during her lifetime.
Spacial and temporal variations in fertility rate
-Today, most countries have an average fertility rate of three children or fewer, whereas in 1950 the world average was five.
-Fertility has fallen throughout Asia.
-Some sub-Saharan African countries still have a high rate of seven or eight.
Define infant mortality rate
The number of deaths of infants under one year old per 1,000 live births per year.
Spacial and temportal variations in infant mortality rate
-Globally, estimates of the average rate vary between 42 and 49.
-This uncertainty reflects the difficulties of recording the data in an accurate and consistent way in different states.
-Afghanistan had the world’s highest rate in 2015 (115 per 1,000).
Graph showing falling fertility in Asia between 1950 and 2014
What does the term ‘population structure’ refer to?
The division of a population into a series of groups according to age and gender.
How is population structure shown?
As a population pyramid for a particular historical year.
How do population pyramids work?
-People are divided into cohorts (age groups) placed either side of the vertical axis, with males on one side and females on the other.
-The size of each age group can be shown either as an actual number (in thousands or millions) or as a percentage of the total population.
Define population structure
The make-up of a population in terms of age, gender, occupation, ethnicity or any other selected criterion.
What is a population pyramid?
A type of bar chart used to show the proportion of males and females belonging to different cohorts (age groups) for a place or country.
What do population pyramids allow us to see?
-How fertility rates and life expectancy have affected a country or smaller-scale place’s population structure.
-We may also be able to see what the effects of past migration, wars, disasters, economic recessions or epidemics have been on particular age groups, or men and women.
Example of how population pyramids can show economic changes
-Most European population pyramids for 2015 show a dip in the number of people aged 40 compared with those aged 45: this reflects a global economic crisis in the early 1970s which led many couples to delay having children.
-As a result, fewer babies were being born in 1975 (the people aged 40 in 2015) compared with 1970 (the people aged 45 in 2015).
When comparing the population pyramids of different countries, which important characteristics can be identified to offer clues about their relative levels of economic development?
-Concave sides
-A wide base
-Perpendicular sides
What do concave sides indicate on a population pyramid?
-This can indicate low life expectancy and a very high death rate.
-This is because few individuals survive to move from one cohort to the next (but note that concave sides for a city’s population pyramid might be caused by youthful in-migration rather than high mortality).
What does a wide base indicate on a population pyramid?
-A relatively high birth rate but low life expectancy.
-As a result, the pyramid narrows rapidly because large numbers of those born are not surviving to reach an older age.
What do perpendicular sides indicate on a population pyramid?
-That the majority of those born survive to an old age.
-This indicates a middle- or high-income county.
One common feature of most age-sex pyramids is more ___ surviving into the oldest cohorts.
Women than men
A population pyramid with annotations that explain irregularities
Contrasting population pyramids for a low-income and middle-income country
What is the dependancy ratio?
-A shorthand measure that compares the proportion of a population that is economically ‘non-productive’ with the proportion that (in theory) generates wealth.
-In practical terms, the youngest and oldest cohorts are unproductive dependants whereas the middle-aged groups are wealth producers.
What does the dependancy ratio express?
The relationship between the active and inactive segments of a society.
What formula is used to calculate the dependancy ratio?
What does a high dependancy ratio of around 60-70 suggest?
-A lack of balance.
-It indicates that there are relatively high numbers of dependants in comparison with working taxpayers.
Why is the dependancy ratio changing in many HICs and emerging economies?
-Because the numbers of retired people is increasing.
-For instance, only 60 per cent of UK citizens are of working age.
What do taxes on the wages of working people help pay for in the UK?
The state pensions of the 21 per cent who are retired; the costs of schooling the young; and healthcare costs for both dependent groups.
In what country is dependancy predicted to become an even greater challenge?
Japan
Graph showing the changing dependent population in Japan between 1950 and 2050 (projected)
Why is the dependancy ratio a very crude and potentially unreliable measure?
-The age of 15 is a poor choice of dividing line for youthful dependency: in many countries, young people remain at school or college until later.
-The proportion of women who work and pay taxes that fund services for the elderly varies greatly between countries. This is not to say women who do not undertake salaried work should be classed as ‘dependent’. More often than not, unsalaried working-age women are playing an essential (if unpaid) social and economic role that involves looking after children and managing households.
-Many children in some middle- and low-income countries do not attend school. They work instead, despite United Nations actions to prevent this from happening.
-Many elderly people in developed countries actively create wealth. Many retired people own sizeable assets such as rental properties or company shares, which generate an income. Others continue to work
What is the demographic transition model (DTM)?
A generalized attempt to establish linkages between a sequence of population changes occurring over time and the economic development of a country.
What happens to CBR and CDR over the years as a country develops economically and the population changes?
They are both lowered. There are many possible reasons for this.
What does the DTM show?
How a country’s population changes over time as it develops economically.
Describe the different stages of the DTM
Stage 1: Stable small population with a high CBR and high CDR
Stage 2: Rising population with a high CBR and a decreasing CDR (e.g. Niger)
Stage 3: Rising population with a decreasing CBR and a further decreasing CDR (e.g. India)
Stage 4: Stable high population with a low CBR and a low CDR (e.g. USA)
Fifth stage of the DTM
-In recent years, a fifth stage has emerged as additional changes to the CBR and CDR have been observed.
-Stage 5- Decreasing population with a CBR lower than the CDR
Diagram showing the demographic transition model (DTM)
Diagram showing the demographic transition model (DTM)
Reasons why CBR falls over time as a country develops
-Emancipation of women
-Political changes
-Compulsory education
-State healthcare
-Secularization
-Materialistic society
-State welfare
-Decline of the family as a unit of production
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Reasons why CDR falls over time as a country develops
-Improved food supply
-Healthcare
-Hygiene, sanitation, and safety
Explain why the emancipation of women is a reason for why CBR has fallen over time in many places
Over time, women become more independent and choose to limit their family size, especially if they have career ambitions.
Explain why political changes are a reason for why CBR has fallen over time in many places
New laws increasing the age of marriage will reduce the number of births.
Explain why compulsory education is a reason for why CBR has fallen over time in many places
Well-educated people understand fully what the consequences of an unwanted pregnancy might be for their lives and careers; they are also aware of the availability of contraception.
Explain why state healthcare is a reason for why CBR has fallen over time in many places
Government programmes may try to reduce teenage pregnancy and disease transmission by encouraging use of contraception.
Explain why secularization is a reason for why CBR has fallen over time in many places
In some countries, a weakening of religious beliefs has led to changing attitudes towards abortion and birth control.
Explain why an increasingly materialistic is a reason for why CBR has fallen over time in many places
In a consumer society, the cost of raising a child grows because of the expense of purchasing clothing, toys, holidays and technology
Explain why state welfare is a reason for why CBR has fallen over time in many places
In many countries, people no longer rely on children to care for them in old age because the state provides healthcare and pensions.
Explain why the decline of the family as a unit of production is a reason for why CBR has fallen over time in many places
As countries develop, family life is no longer organized around subsistence farming. It may therefore make less economic sense to have many children.
Explain why improved food supply is a reason for why CDR has fallen over time in many places
Agricultural revolutions may include (1) the intensification of farming and increased food yields on existing lands and (2) the extensification of production to make use of remoter areas as transport infrastructure improves.
Example of how improved food supply is a reason for why CDR has fallen over time in many places
For instance, between 1650 and 1750, important changes were made to crop rotation systems in Europe, allowing additional food to be grown.
Explain why healthcare is a reason for why CDR has fallen over time in many places
-Disease prevention and treatments have improved globally.
-Well-planned economies can provide comprehensive care (e.g. the UK’s National Health Service).
-Emergency services/ambulances can provide immediate help for injured people.
Example of how healthcare is a reason for why CDR has fallen over time in many places
Immunization against polio has led to its eradication in many states; smallpox has vanished.
Explain how hygiene, sanitation, and safety are reasons why CDR has fallen over time in many places
-When sewer systems were installed in nineteenth-century European cities, life expectancy rose.
-Globally, primary school education aims to raise public awareness of the means by which diseases are transmitted.
-Most countries have health and safety laws that regulate many aspects of everyday life, including: road safety and seat-belt use; rules about smoking and alcohol use; fire exits for buildings; safety tests for technology and toys.
-We belong to risk-averse societies.
Which falls first in the DTM: the CBR or the CDR?
-The crude death rate falls first (as food supply improves and medicine becomes available).
-Only much later does the crude birth rate fall (when women finally begin to produce fewer children as a result of more progressive cultural, legislative and economic changes in society).
Because the CDR falls before the CBR, there is a ___
Time lag between the economically induced fall in CDR and the later fall in CBR, which is governed by cultural and not merely economic changes.
Why is it difficult to predict how long the time lag will be between the CDR and the CBR falling?
Different societies vary greatly in terms of their religious and cultural beliefs.
Example of place where the demographic transition took a long time
Europe (the entire process took approximately 200 years to complete)
Example of a place where the demographic transition was fast
Thailand and China have completed the entire transition more recently in just a few decades.