The big picture

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Demography is the study of populations of any organisms. In human demographics a multitude of factors related to population can be studied e.g. age, race, level of education and economic status. The factors that are relevant in this subtopic are fertility as measured by crude birth rate (CBR) and total fertility rate (TFR) and mortality as measured by crude death rate (CDR). Fertility and mortality control the natural increase rate (NIR) and the doubling time (DT). The rate is a crude rate because it is for the whole population and is not age specific. Both birth and death rates are higher in certain age groups.

The World Population Clock is a very popular curiosity website. It shows the current world population, births, deaths and population growth for the day and the year. The information in Figure 1 was taken at 9.20 am (Beijing time), 30 August 2015. Check out the link and see what the difference is as you read this.

Figure 1. World population clock.

The figures are approximations – guesstimates by the people who study demographics and are based on two major sources of data – the United Nations (Population Prospectus) and the US Census Bureau. Census data about fertility and mortality is used with adjustments made for errors, omissions and inconsistencies in data collection.

The figures show significantly more births than deaths and thus a growing human population. According to the world population clock website that growth rate is 1.13% per year whereas the CIA World factbook says it is 1.08%, not a major difference, but a differences nonetheless. The global growth rate has changed over time and varies by region. Up until the 1800s the world population was steady and below 1 billion, since then however it has sky-rocketed. The least developed regions of the world (especially those in Africa) have very high growth rates whilst the most developed areas such as Europe have declining populations.

The patterns of human population growth are complex as are the factors that influence them. The stable population up until the 1800s is largely due to a balance between fertility and mortality. High birth rates do not cause population growth if they are cancelled out by high death rates. So the world population explosion actually started when we reduced death rates. Better sanitation, vaccinations, clean water and better diets all contributed to a reduction in the death rates. The birth rate can be much harder to reduce. Culture, religion and societal expectations all play a major role in attitudes towards birth control, age of marriage and size of families.

​The population clock is just one way to quantify human population dynamics; there is a wide range of models and indicators that can be studied. Computer simulations and models are used to predict what will happen to the human population in the next 50 to 100 years. Human society is complex and there are many factors that can be studied, from migration rates to religious affiliation.

Can you solve these riddles? (answers at the end of the page)

1. In a pond there is a lilypad that doubles in size every day. If the lily pad will completely cover the pond in 40 days then on which day will the pond be half covered?

Fertility

The crude birth rate (CBR) is the number of births/1000/year – that is how many babies are born each year for every thousand people in the population. The mean global CBR is between 18.7/1000/year and 19.15/1000/year. The lowest mean rates are in the most developed areas of the world whilst the highest mean rates are in Africa (Figure 1).

Figure 1. Crude birth rate by region.

Examiner Tip

You may be asked to calculate the values for CBR and CDR so make sure you understand how to do that.

The CBR can be calculated from population data using the following formulae:

CBR = number of births/total population × 1000

For example: Afghanistan

• Population = 32,564,342
• Number of births = 1,256,006

CBR = 1,256,006/32,564,342 × 1000

CBR = 38.57 births/1000/year

Try for yourself!

Vietnam

• Population: 94,348,835
• Number of births: 1,505,807

The total fertility rate (TFR) is the number of children a woman is expected to have in her lifetime. The critical value for TFR is 2.2 – this is known as the replacement rate. A TFR of 2.2 means that the population will remain stable, less than that and the population will decline and more means it will increase.

As with CBR, the TFR is highest in the least developed area of the world with many African countries having rates of over six children per women (Figure 2). A very large proportion of the European countries and some Asian countries have TFR’s below 2.2, thus they have decreasing populations. According to the CIA world factbook, the country with the lowest TFR in 2014 was Singapore with a rate of 0.8.

Figure 2. Total fertility rate around the world.

International-mindedness

Different countries have different methods of data collection for CBR and TFR.

What factors affect birth rates and fertility rates?

So why the big difference in fertility rates? Well, there are a number of factors that influence fertility in a country. Is wealth and income the main/only factor?

Figure 3. Total fertility rate around the world

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Role of children in the labour force or education

• In the less economically developed countries (LEDCs) children are an economic asset especially in the rural areas where they rarely receive an education but instead work on the farms and enhance family income. This causes high fertility rates.
• In more economically developed countries (MEDCs) children are an economic burden. They stay in the education system until they are at least 16, more often 18 and even if the country has free education there is still a high economic cost to parents of raising the children.

Rates of urban living

Urban living simply means living in towns and cities. There may be a marked difference in the fertility rates between urban and rural areas. Urban areas tend to have lower fertility rates because:

• Space is more limited in urban accommodation.
• Access to healthcare and family planning services is better.
• Access to education is better so more children go to school and stay out of the labour force.

Figure 3. Urban living = less space for large families

Women’s status

In countries where women have a very low status they do not make their own choices about childbearing, working or education. In many of the poorer countries girls do not have access to education. This means they have much poorer chances of employment and a lack the knowledge necessary to control their own fertility. They are seen as child bearers and homemakers. Women with a secondary school education typically have two less children than those with no education. This increases overall fertility rates.

In developed nations women are educated and the traditional role of “housewife” rarely applies. Educated women are far more likely to control their own fertility and seek paid employment outside of the home. Once employed women tend to delay marriage and motherhood and this means less time to have children and hence the fertility rate is lower.

Life style choices and cultural norms

In many developed countries the cultural norm has changed from getting married young (late teens to early 20’s) and having three or four children to later marriages and smaller families. People have become more focused on material things such as good holidays, cars, mobile phones and other luxury items. This is harder to afford with several children so families are getting smaller. There is also the feeling in MEDCs that it is better to have fewer children and focus your resources on giving them the best of everything, rather than spreading the resources between more children.

The infant mortality rate (IMR) and pensions

This seems an unlikely combination – but read on. The IMR is the number of babies that die in their first year of life/1000 live births/year. In most European countries the IMR is around 3 whilst in many African countries it is above 70. So why does this impact fertility? In many LEDCs there are no pensions so parents need to have plenty of children so that at least one of them will look after them in their old age. If the IMR is high people have many children to ensure that some of them survive. It is a bit like an insurance policy.

Family planning and abortions

The availability of family planning, contraception and legal abortions will impact fertility. If any or all of these are easily available women can make the choice as to how many children they have. That choice brings down fertility rates.

Religious beliefs and traditions

Many religions do not allow the use of artificial contraception or abortion and they actively encourage large families saying that children are a gift from god. In many LEDCs many children are seen as a sign of the man's virility and because men control fertility, large families are the result. This combination naturally increases the fertility rate.

Government policy

Countries may have pro-natalist or anti-natalist policies. Pro-natalist policies encourage people to have more children though they are largely unsuccessful and so have a limited impact on the fertility rates. Anti-natalist policies on the other hand encourage smaller families and the use of family planning and contraception. These are often highly successful and bring the fertility rates down, but there are other consequences. E.g. China’s one child policy (Figure 4).

Figure 4. Impact of China's one child policy.

Theory of Knowledge

Is it ethical for governments to control population growth through anti-natalist policies?

Examiner Tip

You will need a case study for a pro-natalist and an anti-natalist country. There are many good ones so pick one that interests you.

Mortality

The crude death rate (CDR) is the number of deaths/1000/year – that is how many people die each year for every thousand people in the population. The mean global CDR is approximately 7.89/1000/year. Figure 1 shows that the spatial distribution of CDRs is not the same as CBRs (crude birth rate) in that the most developed countries do not have the lowest death rates. The pattern is similar in that the highest rates occur in Africa where the countries poorest countries are.

Figure 1. Crude death rates around the world.

International-mindedness

Mortality rates vary between countries, consider the role of cultural differences.

What factors affect death rates?

Some of the factors that influence death rates are very obvious, some less so. This section looks at the major factors that impact mortality rates on a global scale. There are others that operate locally for example race, socioeconomic status, occupation, gender and ethnicity are just a few.

Income

The relationship between income and death rate is, to a certain extent fairly straightforward. High-income families have access to good food, healthcare, education, good shelter, electricity and water. All these improve your chances of survival and lower death rates. However, there does come a point where more money does not lower the death rates. Check out the following sub-headings - access to food and other considerations.

Literacy/education

Education is especially important among women, as an educated mother better understands how to look after the children thus lowering child mortality. Education means better access to jobs, an understanding of healthy life style choices and healthy diet and the realization that the more children you have the more resources you must provide for them. Educated parents also have a positive influence on the education and education support their children receive.

Access to food

A balanced diet with the appropriate amount of calories is vital for good health. A balanced diet means the correct proportions from the major food groups (Figure 2). The amount needed from each group and the amount of calories required will depend on age, weight, gender and lifestyle. On average a healthy diet should include 2,000 to 2,500 calories and approximately 70 grams of protein a day.

Figure 2. Major food groups.

Malnutrition is a killer in both MEDCs and LEDCs. The average calorie intake in most MEDCs is in excess of 3,340 calories and this is causing obesity problems. Regular fast food consumption increases fat and sugar intake, which increases the risk of cardiovascular disease and diabetes. This poor diet is due, in part, to higher incomes and the easy availability of food. The result is higher death rates caused by disease and conditions linked to obesity eg. heart disease.

Conversely many people in LEDCs have a calorie intake below 2,200 and a protein intake of less than 60 grams per day. Their diets lack many of the basic vitamins and minerals and are very low in fat and sugar. Such diets cause serious nutrient deficiency diseases and a rise in death rates. The problem is caused by:

• Poor agricultural techniques which impact the quality and quantity of the food available.
• Insect infestation which attack the crops in the field and in storage.
• Poor distribution systems to get the food from the farmers to market.

Availability of health care

In most MEDCs public health care is readily available to the majority of the population and this lowers the CDR. Public health care aims to prevent and treat disease and promote healthy living. It provides an enormous range of services from neighborhood doctors to immunization programmes. The lack of access to basic health care facilities and immunization programmes in many LEDCs is a major cause of elevated mortality rates.

Water supply and sanitation

There are a myriad of water borne killers. If you are interested to know more go to water.org where there are some interesting statistics about the problems caused by poor water accessibility. These problems are exacerbated by poor sanitation. Figure 3 shows the proportion of people globally that have access to clean water and sanitation and compares of urban and rural.

Figure 3. Access to clean water and sanitation.

Examiner Tip

Figure 3 shows a lot of information, interpreting such graphs is a skill that you will need in your exams. Here is a summary of the information in Figure 3:

• Improved water source:
  • Urban areas in both developed and developing countries have better access to improved water sources than rural areas.
  • In 1990 over 90% of the population in urban areas had access to improved water sources, whereas in rural areas it was approximately 60%.
  • There has been very limited improvement in the access to improved water sources between 1990 and 2004.
  • There has been approximately a 5% increase in access to improved water sources in rural areas between 1990 and 2004.
  • There is not much difference in access to improved water sources between urban and rural areas.
• Improved sanitation:
  • Urban areas in both developed and developing countries have access to improved sanitation than rural areas.
  • Developed countries have much better access to improved sanitation than developing countries.
  • There has been very limited improvement in sanitation in developed countries between 1990 and 2004.
  • In 1990 rural areas in developed and developing countries had very poor sanitation, approximately 20% of the population had improved sanitation, by 2004 this number had nearly doubled.

Access to shelter

Lack of protection from the elements will increase mortality rates. If people are exposed to rain, cold, heat and the organisms that spread diseases (rats, mosquitos etc.) then death rates will be higher.

Other considerations

The lifestyle choices in many MEDCs are pushing the death rates up. A major contributor to higher death rates is poor diet but coupled with that is the sedentary lifestyle that is common in many developed countries. Not only do people eat too much of the wrong foods but they drive everywhere, take the lift or moving walkway and generally do little exercise.

MEDCs are more prone to the degenerative diseases that come with making it through to old age e.g. cancer. LEDCs on the other hand, are more prone to infectious diseases that are caused by other organisms e.g. Malaria.

MEDCs also have higher death rates because they have aging populations. No matter how good your diet or the available health care systems, people do eventually die. MEDCs have had high life expectancy for many years and that is now beginning to show in rising death rates.

The CDR can be calculated from population data using the following formulae:

CDR = number of death/total population × 1000

Doubling time (DT) and natural increase rate (NIR)

Examiner Tip

You may be asked to calculate the values for NIR and DT so make sure you know the formulae for these calculations.

Fertility and mortality combine to determine population size and this is known as the natural increase rate (NIR).If fertility is greater than mortality – as is the case on most LEDCs then the NIR is positive. If mortality is greater than fertility the NIR is negative, and is in fact not an increase but a decrease. The NIR is expressed as a percentage.

NIR = (CBR – CDR)/10

For example:

• World CBR: 18.70
• World CDR: 7.89

NIR = (18.70 – 7.89)/10

= 1.08%

That does not sound very much but with a global population of over 7 billion that is actually a lot of new people added to the world every day. With a population of 7 billion a NIR of 1.08% means another 756,000,000 people every year, 207,123 each day, 8,630 per hour or 144 per minute. This growth is not evenly distributed between MEDC and LEDC and that is discussed further in the next subtopic population growth.

Try for yourself!

What is the natural increase rate (2 decimal places) for the following countries.

Japan

• CBR: 7.93
• CDR: 9.51

Tanzania

• CBR: 36.39
• CDR: 8.00

The NIR is used to calculate the doubling time (DT) – how long it will take a given population to double in size. It is this calculation that demonstrate just how scary these seemingly low NIRs can be.

DT = 70/NIR

Theory of Knowledge

Does low income cause high mortality rates or do high mortality rates cause low income? How do we know the direction of cause and effect on the factors that impact mortality rates?

Population growth

Whether a population grows or shrinks is dependent on the balance between fertility and mortality. Figure 1 shows human population growth since 4000 BC. Obviously these figures are estimates, we cannot possibly know exactly what the population is now so we certainly do not know what it was thousands of years ago. So what caused these changes in growth rates and how are they going to change in the future?

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Figure 1. Global population growth

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Early humans were hunter-gatherers so population densities and growth rates were very low. High birth rates were balanced by high mortality and the population remained stable at around three million. Nomadic societies are small, as they must move constantly to feed themselves.

When agriculture emerged around 12,000 years ago the population started to increase and reached approximately 15 million. In 1368 China’s population was around 60 million but had reached 150 million by 1644 and England’s increased by three million over a similar time span. These increases are attributed to the introduction of new crops (maize and cassava) into Asia and Europe from the America’s.

Population numbers fluctuated wildly until the beginning of the modern era in the 1800s. Plagues, war, famine and invasions were common:

• Europe’s population decreased by 50% between the 6th and 8th century due to a plague.
• The Mongol invasion, famine and plague decreased China’s population from 123 million in 1,200 to 65 million by 1393.
• The Black Death in of the 14th century decimated the global population from 450 million in 1340 to 350 million by 1400.
• European settlers and explorers introduced diseases to other parts of the world to which the local populations had no immunity. Diseases such as smallpox measles and the flu wiped out around 90% of the Native American populations.

Figure 2. Smallpox, the killer.

The agricultural and industrial revolutions in Europe saw the death rates fall as a result of improvements in health care, the introduction of vaccinations and better sanitation. Between 1700 and 1900 Europe’s population quadrupled to over 40 million - the beginning of the exponential growth phase of human population. The United States of America went through similar increases.

Many LEDCs experienced very rapid population increases in the 20th century as economic development and improved public health care reduced mortality. China has become the most populace country on earth with 1.3 billion people closely followed by India with 1.2 billion. And the list goes on and on. So, the global population grew almost continuously for over 600 years until the growth rate peaked in the mid 1960s at just above 2%.

Figure 3. Global population distribution.

International-mindedness

Consider the causes of different population growth rates in different areas of the world.

The future?

Demographers (people who study human populations) can be fairly certain of the pattern of past population changes, the future is less clear. The UN population division produced the World Population Projections in 2012, which was revised in 2015. They know that growth rates are now on the decline due to changes in death rates not birth rates. They expect birth rates to stay fairly constant at around 135 million per year whilst death rates are expected to rise and hit 80 million by 2040 hence the decline in the growth rate. From these assumptions the UN projects three possible scenarios – the high, median and low variants (Figure 4).

Figure 4. The UN population projections 1990 - 2050.

Theory of Knowledge

Predictions that are based on human behaviour are doomed to failure. To what extent do you agree with this statement.

The variants are determined as follows:

• The high variant is the worst-case scenario. This would be the global population if death rates fall but birth rates do not.
• The median variant is the most likely scenario as it simply projects current trends into the future using mathematical formulae.
• The low variant is the best-case scenario. This may actually be realistic in view of the fact that the UN is expecting death rates to increase.

Be Aware

The growth rate is declining NOT the global population (which is now over 7 billion and rising).

The unpredictable aspect of any projection is the birth rates. Whilst global birth rates are declining there is great variation between developed (very low birth rates) and developing countries (high birth rates). Added to this is the concept of population momentum and things are hard to predict. Population momentum is to do with the size of the current population. If you have a large population even low birth rates will still add many babies (Table 1) each year.

Consequences of population growth

There has been a great deal of discussion for many years as to the consequences of continued population growth.

International-mindedness

How will population growth impact different countries?

Malthusian and neo-Malthusian theories

Thomas Malthus (1798) wrote an essay in which he predicted the fate of humanity. He argued that population growth is exponential (yellow line in Figure 1) whereas the increase in food production is arithmetic (red line in Figure 1). This naturally leads to disaster when the human population exceeds carrying capacity and population growth outstrips food production. Malthus saw this being resolved by famine and war – a rather pessimistic and inaccurate view of life.

Figure 1. Malthusian predictions.

Malthus' view was reaffirmed by Paul Ehrlich in 1968 when he wrote The population bomb in which he too predicted global famine in the 1970s and 80s.

In 1972 DH. Meadows, DL. Meadows, J. Randers, and WW. Behrens III released the book The Limits to Growth in which they follow the Malthusian idea. They ran computer simulations to show how the exponential growth of the human population will cause problems in relation to finite resources (fossil fuels etc), levels of pollution and food production.

Figure 2. Limits to growth.

Anti-Malthusian theories

These predictions have been strenuously challenged by a number of economists such as Ester Boserup. She argued that advances in agriculture due to the Green revolution had increased food production faster than we could have imagined. Between 1950 and 1984 grain production increased by 250%, which kept pace with population increase. The truth is that globally there is enough food to feed everyone with some surplus. The fact that famine is still a problem locally is due to poor distribution networks not inadequate production.

Figure 3. Ester Boserup's theory.

The economists take on the situation is the “necessity is the mother of invention” and humans can be very inventive when need drives them. In other words when we are really in a difficult position we will solve the problem. There is plenty of evidence to support this view:

• There have been a number of agricultural revolutions – Green, Blue, hydroponics, aquaponics. All increase our food production.
• Medical advances have allowed us to improve life expectancy and life quality for many. The introduction of reliable contraception is reducing population growth.
• Technological advances are giving us solutions to our power requirements – renewable energy.
• Industrial advances allow industry to keep pace with demand.

Figure 4. Hydroponics - growing food without soil.

It must be remembered that the Green revolution was driven by fossil fuels. Fertilizers and pesticides are derived from oil and natural gas. Agricultural machinery and the delivery networks also rely on fossil fuels.

Theory of Knowledge

This section shows three completely different models that can be used to predict the impact of human population growth. How can we know which one will give us better knowledge?

Overpopulation and the environment

Our continued population growth will have far reaching consequences with regards to the human and natural environment. These consequences include:

• Grain prices are increasing as biofuel production replaces food production, this is one of the disadvantages of certain alternative energy solutions.
• Oil prices are increasing and we are turning to fracking, which causes significant damage to the ecosystems in the area.
• The effects of climate change are being felt ever more sharply.
• Agricultural land is being lost to residential and industrial developments.
• There have been food riots in some countries. E.g. 2007, West Bengal, India.
• David Pimentel (Cornell University) estimates that the USA can sustainably feed 200 million people when it already has a population of 300 million.
• According to the UN Food and Agricultural Organisation the world will need 70% more food by 2050 and the absolute number of undernourished people is increasing annually.
• Water is being withdrawn at ever increasing rates depleting aquifers faster than they can be replenished. Melting glaciers further compromise water supplies. The glacier on Kilimanjaro which is disappearing at an alarming rate currently supplies water to the region. If the glacier disappears altogether the regions water supply will be lost.
• Air quality is compromised.
• Increased levels of pollution threaten terrestrial and aquatic ecosystems.
• Fuelwood usage is increasing but supply is decreasing as the growing population is harvesting more fuelwood. This has lead to problems of deforestation and desertification.
• The depletion of stratospheric ozone is threatening many ecosystems.
• Deforestation for urban expansion, agriculture and mining destroys whole ecosystems.
• Over exploitation of our oceans is depleting fish stocks to the point where they can no longer recover.
• Topsoil is being depleted by over-cropping, which will in turn compromise our ability to produce the food we need.

Theory of Knowledge

Compare and contrast the role of emotion and one other way of knowing in the interpretation ofFigure 5.

Figure 5. The future?

Contrasting viewpoints on the issue of overpopulation and possible implications and solutions.

Think about the potential implications of them having this viewpoint...

Examiner Tip

This is quite an emotive subject so make sure you think this one through. Decided if you feel overpopulation is an issue or not - there is no right or wrong answer here.

1. Decide if you think overpopulation is an issue.
2. Make sure you know your arguments for and against.
3. Make sure you can put forward your ideas in a coherent fashion.
4. Find out which other influential people have similar views as you.

Predicting population change

There are a number of ways to predict population change. The UN World Population Prospectus projections were discussed in the mortality section. Computer simulations can also be used but two traditional methods that will be considered here are the population pyramids and the demographic transition model (DTM).

Population pyramids

Population pyramids are also known as age-sex pyramids or age-gender pyramids. They are a graphical illustration to show the age and gender distribution of a population. In developing countries the graph is actually pyramid shaped but in developed countries that is no longer the case.

The graph consists of horizontal bars on either side of the y-axis. Each bar represents five-year age groups e.g. 0-4 year olds, 5-9 year olds and so on to 100+ year olds. The bars on left side of the y-axis represent the number of males in each age group. The bars for females are on the right. The x-axis shows the population in millions/thousands or as a percentage. In ecology this information can be used as an indication of reproductive potential and the likely continuation of the species.

Theory of Knowledge

Discuss the ways of knowing that are used to predict future population growth from population pyramids?

Figure 1. Age gender pyramid for Sierra Leone 2010.

The population pyramid is a snap shot in time and as such gives the history of the population. If you know what you are looking for, these graphs can yield a lot of information including how to predict what direction the population is heading in the future.

The most obvious information is the age and gender distribution for the entire population. In some countries there are fewer females than males in the 0–5 year age group. This is due to the fact that female infanticide is a common practice. Such patterns would suggest falling birth rates in the near future.

Figure 1 shows concave sides to the pyramid and a very large drop in numbers between 0-5 and 6-10 year age groups. This indicates high mortality rates, especially child mortality. From the point of view of prediction this pyramid would suggest a stable population that is unlikely to be growing very fast, high birth rates are balanced by high death rates. Conversely a pyramid with straighter sides means low mortality between age groups and a population that will be expanding rapidly. This is seen in the 20-34 age groups of the Malaysian pyramid (Figure 2).

Figure 2. Age gender pyramid for Malaysia 1990.

Population pyramids may also become narrower at the base – this indicates a falling birth rate. Figure 3 shows that Thailand had a more or less steady decrease in its fertility between 1980 to 2000 the bars are getting progressively smaller meaning less children have been born. Although Thailand has falling birth rates it does have a large number of adults in the reproductive age groups of 15–34 years old. This is likely to lead to a growing population. The Thailand pyramid is also taller and wider at the top than the one for Malaysia - this indicates higher life expectancy and implies lower death rates.

Figure 3. Age gender pyramid for Thailand 2000.

Examiner Tip

You may be given population pyramids of an unknown country and asked to determine whether the population has high or low mortality and fertility rates and what this may mean for the future. You may also be asked to indicated which stage of the DTM it is from (that follows later in this section).

To be able to understand population pyramids it is a good idea to study a few. There is a very good website for population pyramids, click here to access it.

On the website:

• Select report – drop down menu go to population pyramid graph.
• Select a year to start the pyramid - 1990 onwards usually works.
• Select the country of your choice.
• Click submit.

Pick a range of countries from different areas of the world - LEDCs and MEDCs. Check out some of the Middle Eastern ones Qatar, 2000 has a very odd shape. See if you can find out why.

International-mindedness

Look at the population pyramids form two different countries and consider how different EVS'smay have impacted them.

Predicting population change

Demographic transition models (DTM)

The DTM model was developed in the 1920s and was based on the observation (empirical) of the demographic changes in selected countries over the previous 200 years. The 1920s model had four stages but a 5th stage has been added as developed countries have continued to change demographically - this is shown as the dashed line in Figure 1. Based on the assumption that LEDCs will go through the same progression as MEDCs the model can be used to predict population change.

Theory of Knowledge

To what extent can a model based on what happened in MEDCs be used to predict demographic change in LEDCs?

Figure 1. Demographic transition model.

Stages

The stages are characterized by particular crude birth rates (CBR), crude death rates (CDR) and natural increase rates (NIR). They have a variety of names you just need to know their characteristic and be able to explain them. The stages are also associated with particularly shaped pyramids which you should know.

STAGE 1: Pre industrial society

High fluctuating CBR and CDR cancel each other out to give very low to zero NIR. In this stage high death rates were caused by natural events such as disease and famine. High birth rates were the result of lack of awareness of the family planning and the fact that children contributed to family income and and helped with chores within the household. Section 8.1.1 gives more detail about causes of high death rates.

Figure 2. Stage 1 population pyramid (Niger 1990)

STAGE 2: Urbanizing/industrializing

CBR remains high but death rates drop quickly, this causes a significant increase in the NIR and a rapidly expanding population.

Falling death rates were due to:

• Improved food production caused by mechanization and the green revolution.
• Improvements in food storage.
• A greater understanding of the mechanisms of the spread of disease as doctors became aware of the link between disease, water supply and poor sanitation.
• The discovery of penicillin and vaccination to treat infection and prevent disease.
• Access to basic health care and education.

Figure 3. Stage 2 population pyramid (Bangladesh 2005).

STAGE 3: Industrial

In stage three the death rates continue to fall and the birth rates start declining as well. The start of this stage sees the highest NIR of all stages, as there is a large gap between CBR and CDR. The fall in birth rates was due to:

• Availability of contraceptives and an understanding of the concept of family planning along with an improvement in the status and education of women.
• A ban on child labour. Parents began to invest in their child’s education making children a financial burden.
• The other reasons discussed in 8.1.1 became relevant.

Figure 4. Stage 3 population pyramid (Argentina 2000).

STAGE 4: Post industrial

By this stage birth rates, death rates and NIR are all low. However the population is already large having gone through a period of high growth.

Figure 5. Stage 4 population pyramid (Brazil 2000).

STAGE 5: Post industrial

Death rates now exceed birth rates due to an increase in the so-called lifestyle diseases e.g. low exercise and high levels of obesity causing cardiovascular diseases. An aging population ensues as the large numbers caused by high birth rates in stages 1 and 2 are now into old age. This is a problem because the falling birth rates of stage three mean few workers to support the growing aged population.

Figure 6. Stage 5 population pyramid (Japan 2000).

Criticisms of the DTM

The applicability of the DTM as a tool for predicting population change is questionable. The MEDCs are at the end of the model and are actually being observed to develop the model further and LEDCs may not follow the same pattern because:

• The model is Eurocentric/MEDC based and the relationship between economic development and population growth does not seem to be the same in LEDCs.
• Some LEDC’s are going through the stages much faster as the medical advances have been made, contraception is already in existence and education is widespread.
• It does not take account of natural disasters, epidemics such as AIDS or wars etc.
• It does not take into account government policies designed to manage the population.
• It does not factor in migration, which can have a significant impact on population change.
• Cultural and religious factors have maintained high birth rates in many LEDCs so they are stuck in stage 2.

Theory of Knowledge

LEDCs are stuck in stage 2 of the DTM and that is a problem. Discuss.

Development policies

As discussed earlier in this subtopic, there are many factors that impact fertility and mortality. Any government policy that either directly or indirectly impacts these factors will impact human population dynamics.

Theory of Knowledge

Educating women causes the country to develop. Development of the country will ensure that women are educated. Which one of these statements is true?

Indirect impacts on human population change

The Millennium Development Goals (MDGs) were established by the United Nations in 2000. They are a set of eight international development goals. All 189 UN member states and 23 international organisations committed to achieving the MDGs. You do not need to know about the MDGs but if you are interested go to the UN website.

Millennium Development Goal 2: “Ensure that, by 2015, children everywhere, boys and girls alike, will be able to complete a full course of primary schooling”.

As soon as a government introduces free compulsory primary education the birth rates will decline. Free education alone does not have the same impact as many parents prioritise having children as free labour over educating them. If however primary school is free and compulsory then more children will attend and they cease to be an economic asset.

Education has far reaching consequences as regards to fertility and mortality. Figure 1 shows some of the links between education and fertility and mortality.

Figure 1. The possible impact of education policy.

"Women who are educated, economically engaged, and in control of their own bodies can enjoy the freedom of bearing children at their own pace, which happens to be a rate that is appropriate for the aggregate ecological endowment of our planet." - Ozzie Zehner

Millennium Development Goal 3: "Eliminate gender disparity in primary and secondary education, preferably by 2005, and in all levels of education no later than 2015".

The quote by Ozzie Zehner really sums up the impact of any government policy that changes the status of women. Although he is talking about environmental impact, the impact on demographic change is significant. Check out 8.1.1 for details.

When a country changes the marriage age, birth rates will change. If marriage age is raised then birth rates fall but if it is reduced then birth rates can rise.

The introduction of state pensions has a direct impact on fertility as it reduces the need to have children as an insurance policy for old age. Additionally, any government policy that introduces health care and water supply and sanitation networks will reduce mortality.

Direct policies

Direct governmental policies that that impact demographics are related to fertility. Policies may be pro-natalist ones that increase fertility rates or anti-natalist ones that decrease fertility rates.

Anti-natalist strategies

Tax/welfare disincentives

Strong disincentives were commonly associated with the one child policy of China.

• Increase taxes for families that have more than a set number of children.
• Charge for education and health care for extra children.
• Remove child-care facilities for families with too many children.

This is generally effective at reducing the birth rate as it makes the cost of having children too great. It is beneficial for the government as it reduces the state costs of providing schooling and health care for children. This means more money can be invested in other areas of development.

Negative impacts include problems of an aging population, selective abortions, and the abandonment of babies. This is due to the “need” for male children to continue the family name, inherit the family wealth or work on the farm. In China this has also resulted in spoilt children because parents are only allowed to have one child they dote on that child, give them everything they want and do not want to discipline them effectively. This is further compounded by the fact that each child has four grandparents to dote on them.

The one child policy was relaxed in October 2015 - read more details from The Guardian.

Figure 2. China's one child policy.

Raise awareness

Some countries use less direct methods to reduce fertility and slow population growth.

• Educate the population about the impacts of high birth rates and the benefits of small families.
• Campaigns and education programmes about family planning and the use of contraception.
• Provision of family planning services with free contraceptives, abortions or sterilization.

These techniques have been effective at reducing the birth rate in places like India and Thailand. They are slower to take effect than strict financial disincentives. They may also be a problem in that the use of contraception is against cultural or religious beliefs.

Emancipation of women

As discussed in 8.1.1 changing women’s status rapidly reduces the fertility rates of a country. This is because:

• Once women are able to control their own fertility they realise the birth rate drops.
• Once women are educated and move into the workplace, marriage and childbirth is usually delayed leaving less time to have children.
• Once a couple benefits from two wages it is hard to give up the luxuries that brings.

The emancipation of women is considered one of the most effective ways to bring down the fertility rate. The added benefit is more people in the work force, which is very useful as the population ages. However, there are problems in traditional male-dominated societies where the males do not want to lose control.

All anti-natalist policies will eventually cost the government financially. An effective policy will reduce birth rates and after 15 to 20 years that will mean a reduction in the working age groups. Previous higher birth rates and effective health care reduces death rates and an aging population results.

All anti-natalist policies can run up against issues with traditional cultural and religious values. In many LEDCs big families is the norm, male children are a sign of virility and children are a blessing. These long held beliefs are hard to overcome so the fall in CBR can be very slow.

Figure 3. World religions.

International-mindedness

Some countries have pro-natalist policies and others have anti-natalist policies. Consider what has caused this and why it is linked to development.

Pro-natalist policies

These policies tend to be less effective than the anti-natalist policies – it is difficult to persuade many women that having lots of babies is a good idea. It is also hard to convince people to change their lifestyles.

Tax and welfare incentives

These can also be used as a pro-natalist incentive and the strategies are essentially the opposite of the anti-natalist ones:

• Give tax breaks to families that have more children.
• Make education and health care free for all children.
• Give free housing or upgrade existing housing for larger families – this strategy is used in Sweden.
• Give parents a child allowance – a set amount of money for every child.
• Increase maternity and paternity leave.
• Provide free public transport (France).

Such policies are rarely effective in the long run. The policies are very expensive for the governments but there is a chance they will avert the problems of an aging population which can be even more expensive.

The increased maternity and paternity leave is very costly to the businesses that have to employ temporary workers and pay the salary of the people on leave.

Figure 4. Paternity leave can be costly to businesses.

Romania did manage to increase the fertility rate for a few years. The Romanian government made contraception illegal and banned the import of all forms of artificial contraception. Romania also banned abortions but that lead to the use of illegal clinics which were unsafe and unsanitary. This was effective for a short period of time but it took a lot of policing and as soon as the strict controls were lost the birth rates dropped very quickly.

Examiner Tip

You may well be asked about the impact of development policies on demographic changes. Make sure you know indirect and direct impacts. If you want the higher grades then you should also find a more detailed case study of a pro-natalist country e.g. Romania and anti-natalist country e.g. China, Thailand.

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