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The Study of Population. Demographics. Two of the most basic factors that affect Population are Birth rates and Death rates. (Birth rates – Death rates = Natural Increase) When B.R. – D.R. = 0, we have a situation called Z.P.G. (Zero Population Growth)
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The Study of Population Demographics
Two of the most basic factors that affect Population are Birth rates and Death rates. (Birth rates – Death rates = Natural Increase) When B.R. – D.R. = 0, we have a situation called Z.P.G. (Zero Population Growth) Highly industrialized nations like Germany, Japan, Italy and the Netherlands are experiencing Z.P.G. or decline (natural decreases do occur). At ZPG, the death rate has stabilized, but it is the birth rate that is dropping. Why?
Reasons Why Birth Rates Drop • Role of Women – careers, education • Contraception • Children are too expensive • More leisure time – don’t have time for kids • Fear of the future – war, terrorism, economic bad times, etc. • A Childless preferred lifestyle – D.I.N.K.S. (Double Income No Kids)
Reasons for High Birth Rates Population growth is dependent upon the Birth rate. High Birth rates occur to offset high death rates (eg. In the animal kingdom, one turtle has thousands of offspring, most will die (1/1000), but the species will survive simply due to the large numbers of new turtles. In poor countries, governments do not offer old age pensions or security. Birth rates are high so that the children can take care of the elderly. More children to help on the farms – free, cheap labour Religious, cultural, traditional reasons
Reasons for a High Birth rate Continued Role of women – women in some countries are considered second class and their sole purpose in life is to stay home and have children. Military and strategic reasons – the larger the population the stronger the military Lack of an education and lack of knowledge of Birth Control
Perspectives On Why Some People Are Concerned With Population • Environment can’t support any more people • Pollution is on the increase • We are running out of resources • Our standard of living will decrease • Massive unemployment, disease, starvation, overcrowding will occur
Perspectives On Why Some People Are NOT Concerned With Population • People against Birth control are called pro-natalists. These are the reasons they give: • Re-distribute the wealth • Re-locate population • Controlling population removes personal freedom (moral issue) and is against most religions, it is against nature • We will find ways of taking care of the extra people • Population will take care of itself – be optimistic
Population Pyramid and the Demographic TransitionModel A model has been created to describe what happens as a country goes through various stages of birth rates and death rates. The model is called the Demographic TransitionModel. A type of graph called a Population Pyramid was created to visually show the relationship of the age structure of a country and its male/female distribution.
POPULATION PRYAMID FOR CANADA Source: http://www.statcan.ca/english/kits/animat/pyca.htm
How The Population Explosion Occurred The population explosion occurred about 200 years ago when birth rates began to increase and death rates start to decline. Death rates began to drop due to better health care, better food supply, a decrease in wars, better sanitation/hygiene. This caused more people reached child bearing age and widened the Natural Increase Gap The wider and longer the gap continued the larger the population grew
In core countries the birth rates eventually started to slow down (Children viewed more as a liability). In periphery countries the drop in birth rates took a long time. In some countries the birth rates still haven’t dropped (Children remain an economic asset in most places).
World-2010 Population 6,892,319,000 Births /yr 140,184,169 /day 384,066 /min 267 Deaths /yr 56,907,606 /day 155,911 /min 198 Natural Increase /yr 83,276,563 /day 228,155 /min 158 Core Countries-2010 Population 1,236,646,000 Births /yr 14,215,211 Deaths /yr 12,125,055 Natural Increase /yr 2,090,156 Periphery Countries-2010 Population 5,655,673,000 Births /yr 125,968,959 Deaths /yr 44,782,552 Natural Increase /yr 81,186,407
Population Momentum In 1960 the natural increase rate was 2% of 3 billion In 1990 the natural increase rate was 1.7% of 6 billion A declining natural increase rate does not mean a declining population Population Momentum: Natural increase is decreasing but the overall population is still increasing. Which is greater?: a. You receive $1000 a day for 30 days ORb. You receive 1 cent on the first day, 2 cents on the second, 4 on the 3rd and 8 on the 4th.
The ‘a’ example will get you $30 000. The ‘b’ example will get you $10 737 418.23! Example ‘b’ grows in a compound fashion. Its growth depends on the previous days growth – that is how population grows.
Birth rates and Death rates are affected by the age-composition of the population and this could lead to some confusion. For example: A population representing a developed country like Canada, may have a large proportion of old people and Canada’s death rate may actually be similar to that of a developing country that is made up of a younger population like India. Birth rates and Death rates are still the most important and easily understood, but it is worth looking at other types of measuring tools like total fertility rate, Infant mortality rate and life expectancy
PopulationProjections Encarta ‘97