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What are the components of the dynamics of population growth (see formula below) and discuss whether they add to population growth or subtract from it.P2 = P1 + B – D + I – OP2 = population in time 2P1 = population in time 1
If the population in time 1 is larger then the population in time 2 is also larger (adds to population growth).B = births
The crude birth rate, the number of births per 1,000 persons. The higher the crude birth rate the higher the population growth.D = deaths
The crude death rate is the number of deaths per 1,000 persons. The higher the crude birth rate the lower the population growthI = in-migrants add to poulation growth
O = out-migrants subtract from population growth
NOTE: For most countries in the world (the United States is a notable exception), in-migration and out-migration do not contribute significantly to the overall balance sheet of population change,
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The crude birth rate, the number of births per 1,000 persons, is a measure of the birth performance of a population. Similarly, the crude death rate, the number of deaths per 1,000 persons, is an indicator of death experience of a population.
- Why are both measures called "crude"?
- "Both measures are called “crude” because they fail to account for the different age structures of populations. (p. 111)
- Why does a developed country like Germany have a crude death rate of 10 while a less developed country like Mexico have a crude death rate of 4?
- Germany has a crude death rate of 10 while Mexico has a crude death rate of 4. You would be incorrect in concluding that life expectancy, medical care, and the overall quality of life are higher in Mexico. Germany’s inflated crude death rate is a statistical artifact of its substantial elderly population. Some 16 percent of the German population is over 65 years of age where the odds of dying are high. In Mexico a mere 5 percent of the population is older than 65 years. Relatively few Mexicans are in age classes where the likelihood ofdying is high, thus, its crude death rate is low. " (pp. 111-112)
- Liberia’s has a crude birth rate of 50 and the crude death rate of 18. What is its rate of natural increase ? What is it's crude rate of natural increase (in percent) ?
- "The crude rate of natural increase is the difference between the crude birth rate and the crude death rate. Take Liberia in western Africa as an example. Liberia’s crude birth rate of 50 and the crude death rate of 18 yield a crude rate of natural increase of 32. Keep in mind that these are rates per 1,000 so an increase of 32 per 1,000 translates into a growth rate of 3.2 per 100 or 3.2 percent." (p. 112)
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A. Explain what happens to
- the crude birth rate
- the crude death rate
- and the population growth rate
at each stage of the demographic transition model.
STAGE 1
- the crude birth rate is HIGH
- the crude death rate is HIGH
- and the population growth rate is LOW
STAGE 2
- the crude birth rate REMAINS HIGH
- the crude death rate DROPS
- and the population growth rate INCREASES
STAGE 3
- the crude birth rate DROPS
- the crude death rate REMAINS LOW
- and the population growth rate BEGINS TO DROP
STAGE 4
- the crude birth rate LOW
- the crude death rate LOW
- and the population growth rate LOW
B. Why does the crude death rate fall in stage 2?
"Modernization disrupts the balance between birth and death rates in the second stage of the demographic transition, which is characterized by declining death rates, continued high birth rates, and rapid rates of population growth. Death rates fall as food is transported from surplus to deficit regions, as housing improves, as knowledge about public health reduces contagious diseases, and as antibiotics, immunizations, and other innovations in science " (P. 113)and medicine significantly prolong life.C. Why does the crude birth rate fall in stage 3?
"In the third stage of the demographic transition, birth rates begin to fall in response tolower death rates, urbanization, and other changes associated with modernization. Fertility falls in modern societies as women derive status from activities other than childbearing and motherhood, and as the cost of raising children mushrooms. Children in modern societies become economically active at much later ages than those in agrarian societies, and marry later. Families learn that it is no longer necessary to have six children if they want three of them to survive to adulthood. In addition, as literacy increases and contraceptive technology improves, people are better able to achieve their desired family size. Ultimately, birth rates decline, and the demographic transition is complete." (pp. 113-114)
D. Why must we be careful in using the demographic transition model to predict the future of less-developed countries currently in the second or third stages?
Although the demographic transition is a compelling and an extremely useful framework for viewing contemporary population change, we must be careful in using it to predict the future of less-developed countries currently in the second or third stages. Their economies and populations are so profoundly different from those of European countries when they went through the second or third stages of the demographic transition that we cannot be sure the demographic transition will be resolved in the same way. During the nineteenth century, most European countries experienced a massive exodus of population to the United States, Canada, Australia, New Zealand, and Latin America. Few such “migration escape hatches” exist now for rapidly growing less-developed countries. In addition, populations in less-developed countries are much larger, densities are higher, and rates of growth are much faster. The death rates of less-developed countries fell much faster during Stage 2 of their demographic transitions than they did for the more-developed countries (Figure 5.4). For instance, the death rate of England declined gradually over a century or more with invention and diffusion of scientific improvements in agriculture, medicine, and modern sanitation. Comparable declines in less-developed countries such as India occur more quickly as countries acquire mortality-reducing technologies from more-developed countries. The steeper drop in death rates translates into growth rates that are higher than any experienced in the history of more-developed countries. Also complicating completion of the demographic transition today is the nature of age structures in lessdeveloped countries. There is momentum for continued population growth built into the extremely young age structures currently found in less-developed countries. Put simply, this means that future population growth cannot be avoided, even if countries are able to achieve small family sizes immediately. Take China as an example. Strict family planning policies in China have reduced the average number of children to 1.8, lower than the 2.0 children per family average in North America. And still, the population of China continues to grow at a rate of .9 percent annually because of the large number of people in reproducing ages. (pp. 114-115)
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Look at each of the following population pyramids. What can you tell from the shapes of them about the country's:
- population growth rate? High or low? Declining? Why?
- birth rates? Why?
- death rates? Why?
- Which countries have high amounts of demographic momentum? Why?
A.
ANSWER:
- population growth rate? High or low? Declining? Why?
Probably declaining. See how the base has been getting smaller for the past 24 years
- birth rates? Why?
low - the base is getting smaller
- death rates? Why?
Probably high. Look at the large proportin of the population over age 65 at the top of the population pyramid
- Which countries have high amounts of demographic momentum? Why?
Very little demographic momentum. the base of the pyramid is not large compared to the rest.B.
ANSWER:
- population growth rate? High or low? Declining? Why?
High, but beginning to decline. I call this the Hershey Kisses shape. Look at the base of the pyramid
- birth rates? Why?
Declining. This accounts for the Hershey Kisses shape
- death rates? Why?
Probably low. Only a small proportion of the population is over age 65.
- Which countries have high amounts of demographic momentum? Why?
Ther is still a significant amount of demographic momentum. The populaitn will continue to increase even though the birth rates are declining be cause about half of the populaitn is under the age of 24. they will be having children for many years to come.C.
ANSWER:
- population growth rate? High or low? Declining? Why?
Very high
- birth rates? Why?
High. The base of the pyramid is getting larger and larger.
- death rates? Why?
Low. The proportion of the population over age 50 is very low.
- Which countries have high amounts of demographic momentum? Why?
There is a lot of demographic momemtum. Most of the population is in their chid-bearing years or youngerD.
ANSWER:
- population growth rate? High or low? Declining? Why?
High, but declining
- birth rates? Why?
High, but declining
- death rates? Why?
Probably quite high even though only a small percent of the poplaiton is old because of AIDS.Our chapter on AIDS (chapter 3) discussed the devastating evvect that this diseade is having in Africa. "In Zimbabwe, a country of about 112 million people in Southern Africa, over 900,000 children have been orphaned by the AIDS epidemic. " (.p. 70)
.[Right click on image and select "View Image" to enlarge.]
- Which countries have high amounts of demographic momentum? Why?
I would guess that there is not a lot of demographic momentum since " . . .unlike diseases that tend to target infants and the elderly, AIDS kills sexually active adults in the prime of their lives." (p. 69)E.
ANSWER:
- population growth rate? High or low? Declining? Why?
Population growth rates are relatively low. We do not see the pyramidal shape typical of rapid popuation growth.
- birth rates? Why?
low
- death rates? Why?
low. the top of the pyramid is still quite small.
- Which countries have high amounts of demographic momentum? Why?
Still some demographic momentum.
- How would you explain the large numbers of men between the ages of 20 and 60 especially compared to the number of women in these age groups?
This is because of the large numbers of "guest workers", probably from Pakistan and India, who have come to work in the oil-based economy of this Persian Gulf state.The population pyramids for this questions were fopund online at: http://www.census.gov/ipc/www/idbpyr.html. You may want to take a look at this website
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A. What are some of the significant causes of declines in total fertility rates in less developed countries?In India " . . .there is definite evidence that fertility has fallen since the early 1970s. The total fertility rate—the average number of children a woman would have under current age-specific fertility rates—provides the best indication of fertility change over time. From a six-child average in the 1960s, the total fertility rate has fallen to 3.3 today (Figure 5.9). While this decline is substantial and significant in the context of the country’s rural roots and traditional culture, fertility remains far above the replacement standard of two children per woman that prevails in societies that have completed the demographic transition.Pivotal factors in fertility decline have been an increase in the average age at marriage for women from 16 in 1961 to about 20 today, and higher rates of contraceptive use, from 13 percent in 1970 to 48 percent today. One of the biggest barriers to further fertility decline is the low status of Indian women.
Evidence from the rest of the world shows the strong link between women’s status and fertility." (p. 121)
The overwhelming trend is for fertility to decline over time. We know this from comparing current with past family sizes, by comparing the low fertility in more developed countries with the high fertility in less developed countries, and by comparing social and economic groups within countries. It is almost always the most educated, well-off class that has the lowest fertility. Fertility decline worldwide has been linked to declining rates of infant mortality; economic shifts away from agricultural to more urban-based activities; rising levels of education, particularly for women; increased participation of women in the work force; and the widespread availability and adoption of contraception.
B. What is meant by "development is the best contraceptive" (p. 122) ?
"In the mid-1970s, frustrated by slow progress toward fertility reduction, many government officials rejected family planning as a means to slow population growth. At the 1974 World Population Conference in Bucharest, it was the Indian delegation that articulated the now-familiar argument that “development is the best contraceptive.” Their notion was that contraceptives are only a means to an end—a means to help people achieve the family size they desire, however large that size may be. Without development and all that it includes— education, rising income, upward mobility, and urbanization—the view was that family planning would be unable to reduce fertility. This view has been moderated subsequently as Indian officials—and officials all over the world—see that family planning programs can reduce fertility even without the obvious benefits of development." (p. 122)
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A. The textbook says: "Although the demographic transition is a compelling and an extremely useful framework for viewing contemporary population change, we must be careful in using it to predict the future of less-developed countries currently in the second or third stages." (p.114) WHY must we use caution?Although the demographic transition is a compelling and an extremely useful framework for viewing contemporary population change, we must be careful in using it to predict the future of less-developed countries currently in the second or third stages. Their economies and populations are so profoundly different from those of European countries when they went through the second or third stages of the demographic transition that we cannot be sure the demographic transition will be resolved in the same way. During the nineteenth century, most European countries experienced a massive exodus of population to the United States, Canada, Australia, New Zealand, and Latin America. Few such “migration escape hatches” exist now for rapidly growing less-developed countries. In addition, populations in less-developed countries are much larger, densities are higher, and rates of growth are much faster. The death rates of less-developed countries fell much faster during Stage 2 of their demographic transitions than they did for the more-developed countries (Figure 5.4). For instance, the death rate of England declined gradually over a century or more with invention and diffusion of scientific improvements in agriculture, medicine, and modern sanitation. Comparable declines in less-developed countries such as India occur more quickly as countries acquire mortality-reducing technologies from more-developed countries. The steeper drop in death rates translates into growth rates that are higher than any experienced in the history of more-developed countries. Also complicating completion of the demographic transition today is the nature of age structures in lessdeveloped countries. There is momentum for continued population growth built into the extremely young age structures currently found in less-developed countries. Put simply, this means that future population growth cannot be avoided, even if countries are able to achieve small family sizes immediately. Take China as an example. Strict family planning policies in China have reduced the average number of children to 1.8, lower than the 2.0 children per family average in North America. And still, the population of China continues to grow at a rate of .9 percent annually because of the large number of people in reproducing ages. (pp. 114-115)B. Why must one also exercise caution when using a population simulation model? (p. 126)
"It is important to recognize that any population simulation or projection is hypothetical in nature. One must exercise caution in performing, reporting, and interpreting simulations. One of the dangers of projecting future population change is assuming that various demographic parameters will stay the same in the future. Fifty years ago, few demographers would have imagined European countries with fertility rates barely above 1, or that a disease called AIDS would kill tens of millions of people in Africa. Fifty years from now, future demographers might say that no one foresaw the dramatic increase in life expectancy that resulted from artificial organs, a cure for cancer, or the mapping of the human genome— changes which would render most of today’s population projections too low." (p. 126)
Match the population pyramid with the verbal description of a country's demographic composition
description of a country's demographic composition Pop. Pyramid “A country at close to ZPG (zero population growth)”
“A country that has undergone a recent shift from high to low fertility”
“A country with a declining population”
“A country with many temporary immigrant workers”
“A country which shows the demographic effects of World War II”
“A country with rapid population growth”
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"Using the understanding you have gained by projecting India’s population pyramids into this hypothetical future, give a carefully worded explanation of how it is possible for a population to continue growing for several generations after women begin averaging only 2 children each. It may be particularly helpful to review your answers for Scenario 2 in Activity 2. Using the understanding you have gained by projecting India’s population pyramids into this hypothetical future, give a carefully worded explanation of how it is possible for a population to continue growing for several generations after women begin averaging only 2 children each. It may be particularly helpful to review your answers for Scenario 2 in Activity 2."Population growth is the difference between the number of births and the number of deaths in a population. Growth is determined both by the rate at which births and deaths occur and by the sizes of the population at risk of giving birth or dying. Most developing countries have age-sex pyramids with steeply concave sides, large bases, and small tops. What this means is that there are huge numbers of women about to enter their reproductive years. There are, however, very small numbers of persons (both male and female) at the top of the pyramid where the risk of death is high. As a result, there will be many more births than deaths in the population, even if the number of births per woman is low. In China, for example, the total fertility rate is 1.8 (below replacement levels) and yet the population continues to grow.Consider also the case of India. The “instant replacement level” scenario demonstrates what happens if India were to achieve replacement fertility (the total fertility rate = 2.4) instantaneously. A total fertility rate of 2.4 means that the average Indian women has on average 2.4 children, and she and her husband/partner are having just enough children to replace themselves in the next generation. Even at replacement fertility, the population growth of India would continue until the year 2060, and the population would grow to over 1476 million. It takes many years for the large population base of today to work itself upward into older age groups where deaths typically occur. Only then will deaths equal births and the population achieve ZPG or Zero Population Growth.
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