Understanding Population Change Two useful tools we have that can help us understand causes/reasons for population change are: 1) Population Pyramids 2) Demographic Transition Model

Population Pyramids  A graph that shows the age and sex structure of a population  4 main models or “shapes”: (Fig 13-11)  Early expanding  Expanding  Stable  Contracting  Each shape is typical for populations at different stages of population development

 Shows percentage of people in each age group & percentage of males and females in each age group  Useful – helps predict future population trends  i.e. if few women of childbearing age, population may decrease due to low birth rate

Demographic Tools - Population Pyramids  Show population structures of countries  Provide insight into “problems” and give reasons for shifts in population trends  Most basic: age-sex structure – shown in population pyramids

Population Pyramids

Population Pyramids - Growth

Canada Population Pyramid  What pyramid model does Canada have?

Expanding

Early Expanding

Stable Japan

Demographic Transition Model (DTM)  Describes population change over time or transitions, in birth rates and death rates in industrialized societies over the past 200 years

Demographic Transition Model  The demographic transition model shows changes over a period of time in three elements:  Birth rates  Death rates  Trends in overall population numbers (natural population change)…does not include immigration/emigration  Assumes countries will pass through periods of industrialization on the way to reduced birth and death rates

Demographic Transition Model

 Stage 1 – Pre-Modern – Pre-Industrial  Small population growth  Balance between birth and death rates  Life expectancy LOW

 Rise in population caused by decline in death rate (due to better health care, medicine, sanitation, technology, farming techniques, food supply, education, etc.) while birth rate remains high or rises  Rapid increase in population numbers due to improved medical and scientific advances to sustain life  Without a corresponding fall in birth rates this produces an imbalance, and the countries in this stage experience a large increase in population.  Stage 2 – Urbanizing / Industrializing – Developing Countries

 Stage 3 – Mature / Industrializing  Decline in birth rate results in more stable population  Improved living standards  birth rates fall due to:  access to contraception,  increases in wages,  urbanization,  a reduction in subsistence agriculture,  an increase in the status and education of women,  a reduction in the value of children's work,  an increase in parental investment in the education of children and other social changes  Population growth begins to level off

 Stage 4 – Post Industrial  Characterized by )  Characterized by stability (linked to economic stability)  Population age structure has become older due to low birth rates and death rates  Birth rates may drop to well below replacement level as has happened in countries like Germany, Italy, and Japan, leading to a shrinking population, a threat to many industries that rely on population growth.  The large group born during stage two ages & creates an economic burden on the shrinking working population.  Death rates may remain consistently low or increase slightly due to increases in lifestyle diseases due to low exercise levels and high obesity and an aging population in developed countries.

Demographic Transition Theory  Stage 3: Advanced Industrialization and Urbanization - very little population growth occurs, birth rates and death rates are low.  Stage 4: Postindustrialization - birth rates decline as more women are employed and raising children becomes more costly.

Age Structure of Population  The age structure of a population helps us understand the reasons for population change  Populations divided into:  Children up to age of 15  Working adults from age  Adults age 65 and older  This gives the dependency ratio

Dependency Ratio / Load  Dependency ratio refers to the proportion of the population that is being supported by (or is DEPENDENT ON) the working-age- group (15-65 years old)  Those who work experience a greater financial burden if their country has a high dependency ratio  Africa –  40% of the population under 15 years old  High birth rate  Expanding population  Stage 2 of DTM

Age structure of Canada  Children and older people put pressure on society for:  Medical, education, housing, etc  1996: Canada population included:  21% children, 12% older adults, so…  Dependency ratio of 33%  This means one in every three people in Canada isn’t earning their own money

Age structure of other countries  Consider a country with a much higher birth rate than Canada. What would happen to the dependency ratio?  Much higher!  Bangladesh = 53% (47% children, 6% 65+)  What problems might arise in the future?

Overpopulation  Countries that have too many people for a given resource base and a given level of technological development  When exceeded its “carrying capacity” – level at which land can no longer support its people (i.e. low food supplies)  BRAINSTORM CONSEQUENCES…..

Population Growth – Potential Problems Housing Shortages Increase in Pollution Resource Depletion i.e. - water Energy shortages Technology – energy alternatives? Increase in Unemployment Destruction of Environment Food Shortages Stress on Infrastructure (i.e. roads, schools, hospitals)

WHY? HOW?  Should governments have the power to control the population rate through legal means?

Addressing China’s Crisis  1970s – China had one of the highest population growth rates in the world  1 billion people – 1/5 world’s population at the time  Women averaged 6 children each

China’s Aging Population

China’s Solution  In the late 1970’s, the Chinese government instituted the family planning, or one-child policy  The hope was to eventually reduce the world’s largest population (Fig , pg. 330)  Advantages?  More spending money, reduced pressure on environment, agriculture  Disadvantages?  Aging population, personal freedom compromised, female infanticide

China Population Pyramid  What pyramid model does China have? What do you notice about the male/female populations?

China’s One Child Policy  At this point - # of births reduced to 2.7 children per woman  Government offered rewards to families such as:  Free medical care  Monthly wage bonuses  Preferential housing  Extra pension income

China’s One Child Policy  If family had a 2 nd child – suffered penalties such as  Cancellation of benefits  Fines  Wage reductions

China’s One Child Policy  Problems:  Greater in urban areas due to financial benefits  Rural areas – reply on children as labourers –  Value sons above daughters  Some families resort to infanticide (murder) of female babies  Others ignore policy in favour of their desired family structure Current Status: average 1.8 Current Status: average 1.8 children per woman children per woman Still in effect today Still in effect today

What Else CAN BE DONE???

Responses to Control Population Growth  Improve Technology  Though application of science, including:  Computers  Cell phones  TVs  Countries with higher levels of technology tend to have more developed economies

Responses to Population Growth  Family Planning / Controlling Population Growth Rate  Reduced population reduces strain on resources (natural, economic, etc.)  Leads to a general increase in standard of living

Responses to Population Growth  Increase Resource Base / Lessen Disparity  Use own resources to develop itself – could include:  Work force  Natural resources  Technology  Financial institutions

Responses to Population Growth  Improve Literacy Rates  Giving a population skills to read will improve access to higher paying jobs  This in turn will improve overall quality of life and standard of living

Responses to Population Growth  Increase Opportuniti es for Women  Leads to improved economic development for all