Using the results from A1, we can see that there is the Black American Female Population has a lower CDR and a higher ISDR than the White American Female Population. As we know CDR does not refer to sub-groups that might better represent the population likely to experience the death, which indicates that it takes no account of the age structure of the population. In fact, the age structure of populations can have substantial effects on crude rates. (CDR= ΣPop in age sex group/ Total Population* ASDR) It is obvious that there is a significantly larger proportion of the White American female population in the elder age groups (due to high life expectancy and low exposure to mortality). However, the White American Female Population has a higher CDR at 9.162 than the CDR of the Black American Female at 6.735, therefore, the CDRs we calculated do not accurately account for the age structure of the population.
When we have a look at the data for ASDRs, it is obviously that ASDRS of aged 55-85+ of the Black are much higher than the White, however, the respectively number of females population of the White is significantly larger than the Black, around ten times averagely. Therefore, even if the CDR is higher, it does not adequately indicate a higher mortality rate instead of consideration of ASDRs, which is difference in age structures.
On the other hand, ISDRs（the Indirect Standardized Death Rate）of the two populations was 11.479 per 1000 population for the Black American Female Population, compared to the ISDR of the White American Female Population at 9.162 deaths per 1000 population.) Since ISDR is the data results from population standardization, which is a procedure of adjustment of crude rates to eliminate the effects age structure from the crude rates, it is more appropriate for evaluating different mortalities. The method we use here is the indirect standardization which are standardises on Age Specific
This measure is calculated by using a SMR, which is the mortality ratio between the actual observed number of deaths in the population of interest divided by the expected number of deaths were that population to experience the ASDRs of the base population, which in this case is the White American Female Population.
Since the ADSRs of the base population are lower for every point in comparison to the Black American Female Population, the SMR indicates that the population of interest experienced a much higher actual exposure to mortality in comparison to its standard population, which is the White population.
Unlike the CDR, the ISDR measures standardize the mortality exposure of the population of interest by for differences in age structure. It is a more accurate measure to correctly adjust for differences in age structure between different populations and allows us to more accurately compare the overall mortality exposure of the two populations. B.2.Using the results from A.2, describe the changes in Total Fertility Rate (TFR) and Age Specific Fertility Rates (ASFR) over time among the Black and White American female population. Suggest possible causes or determinants of the changes. How do the values of Net Reproduction Rates (NRR) for the Black and White American female population in 2011 compare to the replacement level? Refer to Appendix A &B
As shown by the table, from 2006 to 2011, ASFRs of age groups 15-29 of the Black female population have declined, while they increased between age 30 to 49 of the Black during this period. In contrast, during this period, the ASFRs of the White female American population have declined for all age groups between 15 to 49, except for an increase of 0.1 in age group 40-44. By comparing the two population in different year, we can see that, in 2006 and 2011, ISDRs of age 15-24 of the Black is significantly higher than the White of same age groups, while In 2006, ISDRs of age 25-49 of the Black is continuously lower than the White of same age groups. However, in 2011, only
two ASDRs of age groups 25-29 and 35-39 of the White were higher than that of the Black. On the other hand, the general trends of TFR of both populations were declining from 2006 to 2011, while the TFR of the Black was continuously higher than the White during this period.
Possible determinants of these common changes between the different ethnicities could include a primary trend among young adults of both black and white to postpone having children. According to data of 2006, among 18-to-24-year-olds, more women than men are enrolled in college in every racial and ethnic group. Increasing college attendance, especially among women, leads to better education, which affects the timing of marriages and first births of women, typically delaying both. Therefore, the U.S. fertility rate may drop further if the share of women attending and completing college continues to increase. (WSJ 2013)
On the other hand, as the flow of immigrants is essential to the maintenance and growth of fertility, a slowdown in immigration into the US has also caused significant drops in the US fertility rate. Moreover, relatively high unemployment rates among African Americans may have played a role in the fertility decline—especially among those with less education and lower incomes.
The fertility rate began to depend on women’s employment and earnings relative to men. (Overberg, P 2013) Women outnumber men in college and make up a growing share of the labor force. This gave rise to the recession which hit male-dominated jobs. As more women become primary breadwinners, fertility decisions are more likely to hinge on women’s earnings than they did in previous decades. A growing reliance on women’s employment and earnings had a greater influence on both the black and white fertility rate in America.
As to data of NRR, the values for both populations in 2011 are 0.924 for NRR of the black and 0.855 of the white, we can see that the Black American female population had a higher NRR than the White population. This may due to national traditions and cultural norms as well as other important determinants such as socioeconomic status, impact on income, education, trend in marriage and access to contraception. (Population Reference Bureau )
Comparing the NRRs for both populations to the replacement level at 1.0, indicates that if ASFRs and ASDRs (and sex ratio at birth) remain constant over time, and there is no migration, these populations eventually will decline in size. B.3. Using the results from A.3, write paragraphs describing and accounting for the changes in the female population of USA between 2006 and 2011 shown by your projection for USA (e.g. how is the total number of population projected to change, which age groups are projected to increase and which to decrease, what are the components of the projected growth, how can relative cohort sizes account for the changes by age).
According to the graphics of Appendix C, which shows the comparison of American female population of different ages from 0-85+ during year 2006 to 2011, we can see that the 2011 projection has a significantly larger proportion of the population in the 45 and over age group. More significantly, there is a projected increase in the number of elderly dependents especially above age group 50-54 in 2011 compared to year 2006.
On the other hand, when having a look at the population of working age referring to the graph, there is a projected reduction from age 35-50 in 2011 compared to year 2006. Therefore, more elderly dependents with less population at work gave rise to larger elder dependency ratio of American females.
The total number of the female US population in 2006 was approximately 154,120,000. While the projected figure has been estimated at 146,092,459, which is approximately an 8 million decline in population as a result of lower fertility, net migration and a constant sex ratio. The expected number of births has been projected to decrease at around the same ratio with the US decreasing fertility rates.
The Census Bureau projects that the U.S. population will continue to grow, to almost 440 million persons by year 2050, albeit at a slower pace than the growth recorded over the past half-century. However, the population projections are rely upon assumptions about the future courses of mortality, fertility, and immigration. Immigration has been another important component of population growth in the United States. The net immigration rate, which is an essential factor to the age-sex structure of US population, has been projected to be positive nearly among all age groups from 0 to 84, except for the eldest age group 85+ (-49).
Average growth rates for each 5-year projection period were positive, but have generally been declining over time. Expressed as a percentage of the population at the beginning of the period, the average population growth rate in the 2006, for example, was 1.7% per annum while it was only 0.9% per year during the 2011.
The Census Bureau assumes that the growth rate will remain positive through year 2050, but will fluctuate over the time period. The current level of 0.8% per annum will increase through 2030 to closer to 0.9% per annum. After 2030 the growth rate is expected to return to 0.8% per annum.( Census Bureau 2013)
Trends in the size and growth of the U.S. population reflect the importance of the role of human reproduction and the fertility factors, as well as the net effect of population migrants of the United States.
According to data of 2006, among 18-to-24-year-olds, more women than men are enrolled in college in every racial and ethnic group. [ONLINE] Available at: http://www.usatoday.com/story/news/nation/2013/02/12/us-births-decline/1880231/.
Fact Sheet: The Decline in U.S. Fertility – Population Reference Bureau http://www.prb.org/Publications/Datasheets/2012/world-population-data-sheet/fact-sheet-us-population.aspx.
Welcome to Human Life Alliance. 2013. Welcome to Human Life Alliance.
the U.S. fertility rate may drop further if the share of women attending and completing college continues to increase. http://content.healthaffairs.org/content/24/2/325.full?sid=bd3dc4c6-be39-441c-b9a8-b9e711ee655f
The Census Bureau assumes that the growth rate will remain positive through year 2050, but will fluctuate over the time period. The current level of 0.8% per annum will increase through 2030 to closer to 0.9% per annum. After 2030 the growth rate is expected to return to 0.8% per annum. https://mail-attachment.googleusercontent.com/attachment/u/0/?ui=2&ik=01f85fe64f&view=att&th=13ec4dc1b157e429&attid=0.0&disp=inline&safe=1&zw&saduie=AG9B_P9thup8H_Ebi0Peyp5cqgdD&sadet=1369102489566&sads=eGFMn9_Rn4kq-DrLuiCtBKINAzw