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# Population Composition & Structure

Published on: Mar 4, 2016
Published in: Technology      News & Politics

#### Transcripts - Population Composition & Structure

• 1. Population Composition & Structure
• 2. Population Composition & Structure <ul><li>The most basic elements of population composition are </li></ul><ul><ul><li>Sex structure </li></ul></ul><ul><ul><li>Age structure </li></ul></ul>
• 3. Population Composition & Structure <ul><li>Sex structure </li></ul><ul><ul><li>The most basic measurement is the sex ratio </li></ul></ul><ul><ul><ul><li>The number of males per 100 females </li></ul></ul></ul><ul><li>Sex ratio = # of males x 100 </li></ul><ul><li>#of females </li></ul>
• 4. Population Composition & Structure <ul><li>If </li></ul><ul><ul><li>Sex ratio > 100, there are more males than females </li></ul></ul><ul><ul><li>Sex ratio < 100, there are more females than males </li></ul></ul><ul><ul><li>Sex ratio = 100, there are equal #s of both sexes </li></ul></ul>
• 5. Population Composition & Structure <ul><li>Important factors that affect the sex ratio are: </li></ul><ul><ul><li>The differences in death rates between males and females </li></ul></ul><ul><ul><li>The differences in net migration by gender </li></ul></ul><ul><ul><li>The sex ratio of newborn infants </li></ul></ul>
• 6. Population Composition & Structure <ul><li>Sex ratios at birth, 2008 </li></ul><ul><ul><li>World = 107 </li></ul></ul><ul><ul><li>US = 105 </li></ul></ul><ul><ul><li>China = 111 </li></ul></ul><ul><ul><li>Mexico = 105 </li></ul></ul><ul><ul><li>France = 105 </li></ul></ul><ul><ul><li>Mozambique = 104 </li></ul></ul>Source: CIA World Factbook
• 7. Population Composition & Structure <ul><li>Sex ratios change as age progresses </li></ul><ul><ul><li>Migration is a very significant factor </li></ul></ul>
• 8. Population Composition & Structure <ul><li>Figures in the text, pp. 56-59 </li></ul><ul><ul><li>“ Frontier” </li></ul></ul><ul><ul><ul><li>Early factor </li></ul></ul></ul><ul><ul><li>Immigration magnets </li></ul></ul><ul><ul><ul><li>More recent </li></ul></ul></ul>
• 9. Sex Ratios by County, 2000
• 10. Population Composition & Structure <ul><li>Age Structure </li></ul><ul><ul><li>Affects economic and social behavior </li></ul></ul><ul><ul><li>Primary determinant </li></ul></ul><ul><ul><ul><li>Birth rate </li></ul></ul></ul><ul><ul><li>Analysis of age structure </li></ul></ul><ul><ul><ul><li>Population pyramids </li></ul></ul></ul>
• 11. Population Composition & Structure <ul><li>Population pyramids </li></ul><ul><ul><li>5 year age groups or cohorts </li></ul></ul><ul><ul><li>A cohort is a group of people who share a temporal (time) experience </li></ul></ul><ul><ul><ul><li>Youth </li></ul></ul></ul><ul><ul><ul><li>Middle aged </li></ul></ul></ul><ul><ul><ul><li>Old aged </li></ul></ul></ul><ul><ul><ul><li>Baby Boomers </li></ul></ul></ul><ul><ul><ul><li>Gen Xers </li></ul></ul></ul><ul><ul><ul><li>Baby Boomerangs </li></ul></ul></ul>
• 12. Post WWII US Baby Boom <ul><li>Born between 1946-1964 </li></ul><ul><li>79 million babies were born </li></ul><ul><li>1930s to early 1940s </li></ul><ul><ul><li>new births in the US averaged 2.3 - 2.8 million/year </li></ul></ul><ul><li>1946 </li></ul><ul><ul><li>3.47 million births in the US </li></ul></ul><ul><li>Peak in 1957 & 1961 </li></ul><ul><ul><li>4.3 million births each year </li></ul></ul>Source: http://geography.about.com/od/populationgeography/a/babyboom.htm
• 13. Number of Births in the US, 1934 to 2000 Source: Wikipedia.com Baby Boom
• 14. Population Pyramids of Rapid, Slow, and Zero Population Growth, 1990 Denmark United States Kenya
• 24. Population Composition & Structure <ul><li>Analysis of population structure is important because </li></ul><ul><ul><li>Future patterns of population growth </li></ul></ul><ul><ul><li>Amongst which age cohorts </li></ul></ul><ul><ul><li>Structure of dependent population relative to the working age/productive population </li></ul></ul><ul><ul><ul><li>Dependency ratio </li></ul></ul></ul>
• 25. Dependency Ratio <ul><li>Ratio of the dependent-age population (the young and the old) to the working age population </li></ul><ul><li>The purpose of the dependency ratio is to measure the # of dependents that each 100 people in the productive years must support </li></ul>
• 26. Dependency Ratio