Populations in Transition

Populations in Transition

1. Population change

   • Annual Growth Rate: This is normally expressed as a percentage and is calculated by subtracting the crude death rate from the crude birth rate. Although the world's population is increasing individual regions or countries can have negative growth. When looking at individual regions or countries growth it is often described as natural increase or natural decrease (natural because it does not include migration). For example if a country had a birth rate of 25 and a death rate of 20, annual growth would be calculated in the following way: 25 (0.025%) - 20 (0.02%) = 5 (0.005%) X 100 = 0.5% (the percentages are calculated by dividing the birth and death rates by 1000, because birth rates and death rates are measured per 1000 of population)
   • Crude birth rates (CBR): The number of births per 1,000 of population within a country.
   • Crude death rates (CDR): The number of death per 1,000 of population within a country.
   • Population distribution: The way the population is spread out. Population may be distributed evenly (in a regular pattern) or unevenly. Virtually all populations are distributed unevenly because of human and physical factors e.g. availability of water and/or jobs.
   • Population density: The number of people living per km2. Countries like Singapore and Hong Kong have very high population densities, while countries like Russia, Canada and Australia have quite low population densities.
   • Fertility
     • Age specific birth rate: The number of birth per 1000 of population for a specific age group e.g. 20 to 25 year olds.
     • General fertility rate: The number of births per 1000 women of childbearing age (15-49 years)
     • Total fertility rate: The number of babies a woman is expected to have in her lifetime. The total fertility rate normally falls as a country develops.
     • Reproductive age range (or child bearing age): Biologically any women between puberty and menopause can have a child. However, it usually means anyone between the ages of 15 and 49.
     • Replacement rate: The total fertility rate needed for a country to replace an maintain its population. The replacement rate is about 2.1.
     • FACTORS CAUSING HIGH BIRTH RATES Primary based economy where children are needed to work on land Women maintained in traditional role of rearing children and taking care of house Lack of education about contraception and family planning The need for children to care for elderly residents Status symbol of having a large family or the need to obtain a male heir Pro-natalist policy Religious or legal practices (no abortion or discouragement of using contraception) Marriage at a young age
     • FACTORS CAUSING LOW BIRTH RATES Availability and affordability of contraception Education about contraception and family planning Reduced infant mortality (less need to have more children to make up for infant deaths) Female emancipation (females are free to get an education and work) Cost of children Anti-natalist policy (like China) Delayed marriage Better care for old dependents (less need for children to care for their parents in old age) Mechanisation of primary sector and shift to secondary and tertiary sectors
   • Mortality
     • Infant mortality rate (IMR): The number of deaths of infants under 1 year old per 1000 live births per year. Child mortality rate: The number of deaths of children under 5 years old per 1000 children. Please not that if a baby is aborted, a female miscarries or baby is stillborn, then they are not included in the statistics above. Age specific death rate: The number of deaths per 1000 of population per year of a specific age group e.g. 50 to 55 year olds. Life expectancy: The average age someone is expected to live when they are born. Japan has the highest life expectancy in the world.
     • FACTORS CAUSING HIGH DEATH RATES War Natural disasters like earthquakes, volcanoes, droughts and floods Disease Poor medical care Shortage of clean water and poor hygiene Unhealthy lifestyle
     • FACTORS CAUSING LOW DEATH RATESI mproved medical care Immunisation programmes e.g. Small pox Clean and reliable water supply Improved diet (higher calorific intake and healthier diet) Improved sanitation and hygiene Improved exercise