Population Change

Natural Population Change A change in the population due to the difference in # of births and the # of deaths. Births – Deaths = Natural Change

Natural Increase - population is growing because the number of births are greater than the number of deaths Births Deaths Population had a NATURAL INCREASE of 700 people. Natural Decrease - population is shrinking because the number of births are less than the number of deaths. * 6300 Births Deaths * Population had a NATURAL DECREASE of 1500 people.

Population Pyramid – graphs that show the structure of a population by age and gender.

Expanding population - population is increasing because of a high birth rate - high death rate (a) or decreasing (b) - pyramid is wide at the bottom - usually indicates undeveloped or developing countries

Contracting population - population is decreasing (d) - low birth rate / low death rate - child-bearing age are not replacing themselves - bottom more narrow than middle - usually indicates developed countries Stationary population - population is basically staying the same (c) - declining birth rate / low death rate - child-bearing age groups are replacing themselves - middle is roughly the width of the bottom - usually indicates developed countries

BIRTH RATE / DEATH RATE Birth rate - the number of births per 1000 people, in a year. BR = births x 1000 population Death rate - the number of deaths per 1000 people, in a year. DR = deaths x 1000 population

Highly Developed Countries Low birth rates. Why? 1. Access to affordable birth control. 2. Health care offers prenatal and family planning education. 3. Educated people have less children. (female education) 4. Educated women work more and have children later in life. 5. As the economy moves away from primary activities less children are needed to help provide income. Low death rates. Why? 1.Better health care reduces death rate. 2.Educated people live longer. 3. Better water supply and sanitation. 4. More access to food – better nutrition. 5. Lower infant mortality rates. 6. Higher standard of living leads to all of the above.

Lower developed/ developing countries have: High birth rates. Why? High death rates. Why? The opposite reasons of why developed nations have low birth and death rates.

DEPENDENCY RATIO Dependency ratio - people under 15 and over 64 who are dependent on the working population. The statistics for population pyramids can give you the data to determine dependency ratio. Dependency ratio = (% under 15 + % over 64) x 100 % Dependency ratio = ( ) x 100 = 73 per Every 100 people in the potential labour force supported themselves and 73 additional people. Usually the population that is expanding has the highest dependency ratio.

GRAYING OF THE POPULATION Graying of the population - when the % of older people in the population is increasing. Factors that contribute to a graying of the population: A. Low birth rate - less young people B. Low death rate - older people live longer C. Young people moving away -higher % of older people D. Better health care -people live longer E. Higher standard of living -people live longer