geography

  Birth and fertility rates
The birth rate is the number of births in a population in a specific period. It is measured using the crude birth rate (CBR). The world birth rate is now 20 per 1,000 (‰), but
 the figure varies according to a country’s level of development.
 The total fertility rate (TFR) is an estimate of the average number of children that a woman has during her
  lifetime (age 15-49).
A minimum of 2.1 children per woman allows generational replacement to take place. But in developed countries today, the rate is only 1.6 children per woman

Demographic indicators
CRUDE BIRTH RATE (CBR)
CBR=
number of births number of inhabitants
x 1,000
x 1,000
 CRUDE DEATH RATE (CDR)
CDR =
number of deaths number of inhabitants
 CHILD MORTALITY RATE (CMR)
CMR =
number of deaths under one year number of live births
x 1,000
x 100
 RATE OF NATURAL INCREASE (RNI)
RNI =
number of births – number of deaths number of inhabitants
 POPULATION DENSITY
Population density =
number of inhabitants

The death rate
The death rate is the number of deaths in a population in a specific period. It is measured by the
crude death rate (CDR).
The death rate has fallen since the early 2oth century. It is now about 8 ‰, but there are great
differences between countries.
As a consequence of the fall in the death rate, there has been an increase in life expectancy. This
  is the average number of years that person expects to live. Life expectancy in the world is about 70 years, but there are differences between men and women, and between different countries.
 The rate of natural increase
Natural population growth is the difference births and deaths. If more people are born than die, the population increases, and vice versa. It is measured by the rate of natural increase (RNI).
A high rate of natural increase is over 2%, and a low rate is under 1%. Today the world’s natural growth rate is around 1.2 %, but there are big differences between countries.
However, real population growth is also influenced by net migration. This is the difference between the number of emigrants and immigrants in a specific period of time.
   Demographic indicators

 

The total number of inhabitants of a place is used to calculate population density. This is the ratio between the number of people and the size of the area they occupy.
Population density is high when a lot of people live in a small area. If the same number of people lives in a very large area, then the population density is low.
Population structure
A population pyramid is a bar graph which shows the age and gender structure of a population.
  Age: the population is divided into young people (0-14 years), working age (15-64), and older people (over 65).
Gender: the population is classified into males and females.

World population stages
 Until the 19th century, world population grew slowly, as in Stage 1. In 1750, there were only 800 million people on the Earth.
Improvements in agriculture, medicine and hygiene in developed countries reduced the death rate and the population increased rapidly, as in Stage 2. By the end of the 1800s, the world’s population reached 1.7 billion.
Population growth accelerated during the second half of the 20th century: from three billion in 1960 to six billion in 1999. This rapid increased is called a population boom.
Today, the world’s population is growing by about 80 million people a year, although the rate is slowing down and it is believed to decline due to an ageing population.
Click for more information
 THE DEMOGRAPHIC TRANSITION MODEL

Recent demographic trends
   The birth rate has fallen throughout the world.
The fertility rate has also fallen. There was a rate of 5 children per woman in 1950,
compared to 2.5 in 2013. In developed countries, the rate fell from 2.8 to 1.6.
There has been a decline in the death rate in most regions. But in counties with ageing populations, this will grow again in the future.
Life expectancy has risen because of advances in medicine, nutrition and hygiene. In 1950, average life expectancy was 46.7 years for men and 48.7 for women. In 2012, it was 68.1 for men and 72.6 for women.
    Regions with low population growth
Developed countries have low population growth, at around 0.2%. Some countries have negative growth, which means they are losing population. For example, Germany had 82.5 million inhabitants in 2003 and 80.6 million in 2013.
These countries have a low death rate, but they also have a very low birth rate (11‰). The birth rate has declined sharply for the following reasons:
    There are more working women, who sometimes find it difficult work and bringing up children.
Contraception is widely available. Families delay having children.
It is expensive to raise a family. Social values are changing.
      As a result of the low birth rate and high life expectancy, many developed countries have an ageing population.
In recent decades, the birth rate has also begun to fall in many developing countries.
 

The decline of the fertility rate. The number of children per woman has fallen all over
  the world.
 – In developed countries, many women go out to work and wait longer to have their first child.
– In emerging and less developed countries child mortality has fallen. Consequently, many families no longer need so many children for economic reasons.
   The increase in life expectancy. People now live longer than in the early 20th century. This is due mainly to advances in medicine and improvement in diet, hygiene and working conditions.
 Regions with ageing populations
Today, life expectancy in developed countries is high: 78 years. Together with a low birth rate, this results in an ageing population. In developed countries, 17% of the population is aged 65 or over.
The population is also growing older in some emerging countries. In Latin America, for example, life expectancy has increased by more than 20 years in the last five decades. At the same time, the birth rate has fallen.
However, in less developed countries life expectancy is low and the birth rate is high. In Sub- Saharan Africa average life expectancy is 56 years, and the birth rate is 39‰. As a result, there is a young population: only 3% of the population is aged 65 or over.
The consequences of population ageing
Population ageing has economic and social consequences:
  Generational replacement does not take place, so

5. Population policies
 High natural population increase can lead to overpopulation. This means that there are too many people for the resources available. This leads to several results. It becomes difficult to produce enough food. There are too many children for schools to work effectively. There are not enough jobs for the adult population. The country cannot provide basic services.
Many less developed countries have implemented birth control policies to deal with overpopulation. However, these policies have had mixed results. For example, population growth has decreased in China and Algeria, but not in India.
Ageing populations in developed countries also create problems. Two types of policies aim to deal with these problems. They focus on encouraging births: they create kindergartens, give subsidies to large families, or reduce parents’ working hours. They also focus on covering social costs by increasing taxes, delaying retirement age or reducing pensions.