Presentation on theme: "Demographic transitions"— Presentation transcript:
1 Demographic transitions Definition: tendency for a population to shift from high birth and death rates to low birth and death rates. Often occurs from economic and social development.Countries are usually classified into two groups:Developed (US, Japan, France)Developing (moderately/less developed): Mexico, Thailand, EthiopiaThese categories usually experience similar population dynamics.
2 Population Paradox: Key terms Total Fertility Rate: Average number of children born to each womanReplacement level fertility: Number of children a couple must produce in order to “replace” themselvesRLF ranges ( ) depending on the country. Why?Infant mortality rates: number of infant deaths per 1,000 live births
3 Population Profiles-bar graph showing the number or proportion of people at each age for a given population.
4 Age structurePopulation profiles shows the age structure of a population, which is the distribution of population by ageThese profiles help demographers project how populations will change over time.shows the age and gender composition of a regionhorizontal axis: divides gender and shows absolute number of people or in percentage of populationmale: left-hand female: right-handvertical axis: age in 5-year or 10-year intervals
7 Population Pyramids and Demographic Stages characteristics shapes of ‘pyramids’wide base (true pyramid)wide middle (bulge), somewhat wider baseurn- or bottle-shapedreversed pyramidPre-reproductive Age: 0-14Reproductive Age: 15-44Post-Reproductive Age: 45 and older
9 Phase 1 (preindustrial stage) high birth rates, high (at time erratic) death rates, low growth ratesstage for much of human history, traditional societies where people were susceptible to disease and family planning was nonexistentpractically no country today
10 Phase 2 (transitional stage) high birth rates, declining death rates, rising growth ratesimprovements in sanitation (water) and medicine, lack of family planningin developing countries such as Iraq, Nepal, etc.Population Momentum: population will continue to grow for years after reaching replacement fertitlity
11 Phase 3 (industrial stage) continued decline of death rates, declining birth rates, growth rates decline from high to lower levelschange in behavior: adaptation to lower death rate, in particular infant mortality rateeconomic change: urbanization (incentive to have fewer children/ China), changes in women’s role, better healthcare
12 Phase 4 (postindustrial stage) Phase 4: low birth rates, low death rates, low growth ratesUnited States, CanadaBetter education, more affluent, cultural attitude toward smaller families, better standard of living
14 What happens after Phase 4? Phase 5?: low birth rates, rising death rates, declining growth rates (if birth rates drop below death rates: negative growth rates)Zero population growth: birth rates equal death rates and there is no growth.Graying population: proportion of elderly is increasingWestern Europe, Japan, Italy, Spain