Review topics for Test 1 Population growth and its effects Death rate Birth rate Be able to Label these axis on the Exam Vital events birth and death registers Since these two events refer to the starting and stopping of life counting these registered events resulted in Vital Statistics American Community Survey A survey that is distributed to 250 000 households each month rather than just once every ten years and which will provide detailed information on American cities and towns annually that used to be available only on a decadal basis in the census long form Annual growth rate Globally the growth rate of the human population has been declining since peaking in 1962 and 1963 at 2 20 per annum In 2009 the estimated annual growth rate was 1 1 LDR countries versus MDR also being able to distinguish the differences in their population pyramids Look at graphs in the power points Ones that are top heavy have a higher elderly population while the ones that are bottom heavy have a higher younger population Japan and Italy are examples of countries that have an older age structure Africa is an example of a country with a younger age structure Age structure understand what it means and its implications for societies how it interacts with fertility mortality and migration Fertility The childbearing performance of individuals couples or groups as indicated by the frequency with which birth occurs in a population Mortality The frequency with which death occurs in a population Migration A change in residence across some specified geopolitical boundary Countries with a younger age structure tend to have more children because of the lower life expectancies As Mortality decreases within a population the number of children comes closer to the average 2 5 children per household How Fertility Determines Structure Two factors determine the number of babies that will be born 1 number of women at childbearing ages 2 age specific birth rates of these women Example of baby boom and bust Fertility does not really have an impact on sex structure however How Migration Determines Structure Can affect both age and sex Impact varies by the geographic area being considered Population of the area determines how much impact migration will have to the area Borders impact how much migration takes place Example of college towns Direct effect only to the degree that net migration is selective with respect to age and sex Indirect effect when selective net migration has a direct impact on population composition which in turn influences fertility which affects age structure Cohort cohort flow Birth cohort is a group of people born during the same time period Cohort flow people of same age are influenced by the same historical circumstances Basic sources of demographic data Census purposes uses errors etc The census is a snapshot of a population once every several years where every individual is to be enumerated or counted In the Us the census happens every ten years The objective is to obtain data about the size composition and distribution of the population There are two ways of counting the population De Jure counting people according to their normal location De facto counting population according to onces geographical location on the day of the census Errors of the census include Content Error problems with the accuracy of the data obtained in the census Coverage Error people are missed or counted more than once Estimation Error Can fix this by a post enumeration survey or by checking through a variety of methods to make sure information is accurate Predicted population trends in general Projections essentially assume that present trends will continue They also implicitly assume that mortality and fertility in the LDRs will follow some version of the sequence we call the demographic transition There are several ways in which a demographer might project the population These include extrapolation methods the components of growth method the cohort component method Modernization and economic development and how they relate to population changes Modernization and economic development relate to population change in that we have improved living conditions and introduced modern medicine and vaccines This has caused a decrease in the infant mortality rate People are now more likely to die from old age and cancer Feminization of old age Women live longer than men in almost every human society In 1950 there were 83 males per 100 females at ages 75 in the United States this declined to only 54 males per 100 females by the 1990 census with a slight rise since then Thus at age 75 and older two thirds of the people alive in the United States are women The difference between male and female LE has been decreasing however o Peak of 7 8 years in 1979 o 5 years in 2008 o It also changes as people age less of a difference of LE at age 65 than birth Projected that by 2050 females will only make up 52 of the population 65 74 85 plus will drop to 61 women o This may affect the number of older women living alone without partners Demographic transition model Leads first to a decline in mortality and then to a commensurate decline in fertility Original Model divided roughly into 3 stages 1 Birth and death rates are high 2 Transition from high to low birth and death rates The growth potential is real ized as death rate drops before the birth rate drops resulting in rapid population growth 3 Death rates are as low as they are likely to go while fertility may continue to decline to the point that the population might decline The demographic transition is really a whole set of transitions health and mortality transition age transition migration transition urban transition fertility transition family and household transition The shift from high to low death rates and then from high to low birth rates As regions experienced development many countries moved from pre transitional to transitional categories Late transition current MDR countries that moved through transition later yet more rapidly Current transitions are following new and different patterns Health and mortality transition The shift from deaths at younger ages due to communicable disease to deaths at older ages due to degenerative diseases Easterlin relative cohort hypothesis The positive relationship between income and fertility is dependent on relative income For example if a couple is doing well and jobs are plentiful they will be able to start their lives younger and have more