1. Human Population
Demographic Study

2. Population Pyramid
A population pyramid, also called age-sex pyramid and age structure diagram, is a graphical illustration that shows the distribution of various age groups in a population

3. Types of Population Pyramid
Stationary pyramid - A population pyramid showing an unchanging pattern of fertility and mortality

4. Expansive pyramid - A population pyramid showing a broad base, indicating a high proportion of children, a rapid rate of population growth, and a low proportion of older people.

5. Constrictive pyramid - A population pyramid showing lower numbers or percentages of younger people. The country will have a greying population which means that people are generally older.

7. Age/Sex Structure
The age/sex structure is also called the population pyramid. This structure or pyramid is a graphic way to show the age and sex composition of a population. The sum of all age and sex groups equals 100 percent of the population.

8. Developing Country

9. The developing countries have a population structure that resembles a pyramid with a broad base of young and a small apex of old. Sudan in 1995 is an example of a pyramid for a developing country.

10. Developed Country

11. The developed countries are beginning to lose their "pyramidal" shape as they become more straight up and down with almost equal numbers of people in adjacent age groups until the ages of high death rates begin after age 65. United States in 1995 is an example of a pyramid for a developed country.

12. Very Developed Country

13. Germany is experiencing a period of negative growth (-0. 1%)
Germany is experiencing a period of negative growth (-0.1%). As negative growth in a country continues, the population is reduced. A population can shrink due to a low birth rate and a stable death rate. Increased emigration may also be a contributor to a declining population

14. Case Study

16. Uses of population pyramids
Population pyramids can be used to find the number of economic dependents being supported in a particular population. Economic dependents are defined as those under 15 (children who are in full time education and therefore unable to work) and those over 65 (those who have the option of being retired).

17. In many countries, the government plans the economy in such a way that the working population can support these dependents. Age pyramid has similar uses to population pyramid.
Population pyramids can be used to observe the natural increase, birth, and death rate.

18. Total fertility rate
The total fertility rate (TFR, sometimes also called the fertility rate, period total fertility rate (PTFR) or total period fertility rate (TPFR)) of a population is the average number of children that would be born to a woman over her lifetime if

19. (1) she were to experience the exact current age-specific fertility rates (ASFRs) through her lifetime, and (2) she were to survive from birth through the end of her reproductive life. It is obtained by summing the single-year age-specific rates at a given time.

20. Replacement rates
Replacement fertility is the total fertility rate at which newborn girls would have an average of exactly one daughter over their lifetimes. In more familiar terms, women have just enough babies to replace themselves.

21. Mortality rate
Mortality rate is a measure of the number of deaths (in general, or due to a specific cause) in some population, scaled to the size of that population, per unit time. Mortality rate is typically expressed in units of deaths per 1000 individuals per year; thus, a mortality rate of 9.5 in a population of 100,000 would mean 950 deaths per year in that entire population.

22. The crude death rate, the total number of deaths per 1000 people
The crude death rate, the total number of deaths per 1000 people. The crude death rate for the whole world is currently about 9.6 per 1000 per year (based on 62 million deaths in 2006, for a population of 6470 million).
The perinatal mortalityrate, the sum of neonatal deaths and fetal deaths (stillbirths) per 1,000 births.
The maternal mortality rate, the number of maternal deaths due to childbearing per 100,000 live births.

23. The infant mortality rate, the number of deaths of children less than 1 year old per thousand live births. The child mortality rate, the number of deaths of children less than 5 year old per thousand live births. The standardised mortality rate (SMR) or age-specific mortality rate (ASMR) - This refers to the total number of deaths per 1000 people of a given age (e.g or 65+).

24. The ten countries with the highest infant mortality rate are:
Angola
Afghanistan
Sierra Leone
Mozambique
Liberia
Niger
Somalia
Mali
Tajikistan
Guinea-Bissau

25. According to the World Health Organization the 10 leading causes of death in 2002 were:
12.6% Ischaemic heart disease
9.7% Cerebrovascular disease
6.8% Lower respiratory infections
4.9% HIV/AIDS
4.8% Chronic obstructive pulmonary disease
3.2% Diarrhoeal diseases
2.7% Tuberculosis
2.2% Malaria
2.2% Trachea/bronchus/lung cancers
2.1% Road traffic accidents

26. Factors affecting a given death rate
Age of country's population
Nutrition levels
Standards of diet and housing
Access to clean drinking water
Hygiene levels
Levels of infectious diseases
Social factors such as conflicts and levels of violent crime
Amount and quality of health care available

27. Life Expectancy
Life expectancy is the average number of years of life remaining at a given age. Life expectancy is heavily dependent on the criteria used to select the group.
In countries with high infant mortality rates, the life expectancy at birth is highly sensitive to the rate of death in the first few years of life.
In these cases, another measure such as life expectancy at age 5 (e5) can be used to exclude the effects of infant mortality to reveal the effects of causes of death other than early childhood causes.

28. Gender Differences In Life Expectancy
If one does not consider the many women who die while giving birth or in pregnancy, the female human life expectancy is considerably higher than those of men, who, on average, consume more tobacco, alcohol and drugs than females in most societies.

29. In most countries many more men than women commit suicide
In most countries many more men than women commit suicide. In general, men are more likely to be murdered. In wars, many men die in combat as soldiers. Men tend to take more risks than females when driving motor vehicles.

30. Immigration/Emigration
Emigration is the act of leaving one's native country or region to settle in another.
It is the same as immigration but from the perspective of the country of origin.
Human movement before the establishment of state boundaries or within one state, is termed migration.

31. Push factors War or other armed conflict Famine or drought Disease
Poverty
Political corruption
Disagreement with politics
Religious fundamentalism / religious intolerance
Natural disasters
Discontent with the natives, such as frequent harassment, bullying, and abuse
Discontent with immigration rate, causing frequent harassment, bullying, and abuse for home populations
Lack of employment opportunities
Lack of various rights

32. Pull factors Higher incomes Lower taxes Better weather
Better availability of employment
Better medical facilities
Better education facilities
Better behaviour among people
Family reasons
Political stability
Religious tolerance
Relative freedom
National prestige

33. Doubling time
The doubling time is the period of time required for a quantity to double in size or value. It is applied to
population growth
inflation
resource extraction
consumption of goods

34. Examining the doubling time can give a more intuitive sense of the long-term impact of growth than simply viewing the percentage growth rate.
For a constant growth rate of r%, the formula for the doubling time Td is given by

35. Formula for Calculating Doubling Time70
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% Annual Growth