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Population Growth Rate
Complete these exercises with information from the Text.

Text Exercises with Answers

1. Read and study the text and the definition of population growth rate and answer the following questions.

  1. What does population growth rate measure? [Population growth rate (PGR) is the increase in a country’s population during a period of time, usually one year, expressed as a percentage of the population at the start of that period. It reflects the number of births and deaths during a period and the number of people migrating to and from a country.]
  2. If you wanted to get an accurate picture of population growth trends in a country, would you look at the average annual growth rate for a single year, or for a period of years? [a period of years] Explain why. [Looking at growth rates over a period of years helps to counteract any uncommon short term events that might give an inaccurate picture of population trends. For example an epidemic, famine, or war could cause a significant drop in PGR one year, but the change would not be due to any long term shift in people’s behavior, and therefore would not be as pronounced if looked at over a 10 or 15 year period.]  

2. Answer each of the following questions briefly, referring back to the text if necessary.

  1. Why have death rates and birth rates declined? [Death rates have declined largely because people have more access to better health care and better nutrition. Birth rates have declined because parents are more confident that their children will live to adulthood; more people have access to family planning; and more girls are receiving basic educations, and are choosing to start their families later in life and to have fewer, healthier children.]
  2. What causes population momentum? What are its consequences? [Population momentum occurs when a population consists of a large number of young people who are at childbearing ages. Because of their sheer numbers, and because they are having children, population in these countries continues to rise, even if they are reproducing at replacement fertility levels. As a consequence, population momentum does not allow the full effect of a lower PGR to be felt for several decades. The resulting larger population imposes additional demands on a country’s social services, economy, and environment.]
  3. How might increasing urbanization affect environmental conditions in a country? [Increased urbanization can result in increased consumption of natural resources such as trees for lumber and fresh drinking water; more pollution which can affect air and water quality and can have a negative effect on health conditions, wildlife, and vegetation; more "crowding"; and fewer "green spaces".]
  4. To what extent does migration between your country and others, or from rural to urban areas within your country affect your country’s economic, environmental, or social situation? [Answers will vary.]
  5. What sorts of services and support can a government provide to its citizens that will help slow the population growth rate? Explain why you think these strategies may help. [Governments can increase education, especially for girls; offer better family planning services to more people; provide medical insurance, pension plans, and social security; improve health care and decrease infant mortality; and increase people's awareness of problems of rapidly growing populations.]
  6. What might be some reasons why women with a basic education tend to have fewer children? [They may be more aware of family planning options; they have have probably learned about health, hygiene, and good nutrition, so more of their children survive; and they are better qualified to work outside the home and earn money, so they have more options in life and may choose to start families later and have fewer children.]

3. Calculate the annual population growth rate for countries A, B, and C using data provided in the table below and this formula:

Population increase in a year

Population at the start of the year




Annual population growth rate %

Note: Average annual population growth rates for a period of years provide a better picture than annual rates. For this reason, they are used in the Data Table. Calculating any growth rate for a period longer than a year requires more complicated mathematical formulas than the one used to calculate an annual rate.

at the start
of the year
at the end
of the year
during the
rate (%)
Country A
Country B
Country C

4. Population growth rates are small numbers, but they have large effects on population. To see what this means, complete the following exercises.

  1. Assume the world population at the beginning of 1999 was about 6 billion. If the projected 2000 average annual population growth rate for the world was 1.1%, how many more people would be added to the world by 2001. [66 million]
  2. If the 2000 world population grew at .2%, the same projected rate as the United Kingdom, how many more people would be added to the world by 2001. [12 million]
  3. If the 2000 world population grew at 1.7%, the same projected rate as Kenya, how many more people would be added to the world by 2001. [102 million]
  4. Use your answers to questions 3a,b, and c to make a general statement about the relationship between population growth rates and the change in the size of a population. [Even small changes in population growth rates have a significant impact upon the size of the world’s population.

5. Use the calculations and data in the table below to calculate the birth rates, death rates, and population growth rates for three countries and fill in the missing information.

Number of births (%)





Birth rate

Number of deaths (%)





Death rate

Birth rate (%)


Death rate (%)


Population growth rate (%)







growth rate

Country A







Country B







Country C







6. If a population growth rate is low, population is growing slowly. If it is high, population is growing rapidly. To understand what "slow" and "rapid" mean, it helps to look at how long it will take different countries growing at different rates to double their population.

  1. The number of years it takes a population to double can be estimated by dividing the number 70 by that population's growth rate. Calculate the doubling time of populations growing at the rates shown in the key to the map. [Less than 1%, 70 years or more; 1% to 1.9%, between 70 and 36 years; 2% to 3%, between 35 and 23 years; more than 3%, less than 23 years.]
  2. Is three percent a rapid growth rate? Explain. Is two percent a rapid growth rate? Explain. Is one percent a rapid growth rate? Explain. [Answers will vary.]
  3. Use the projected population data in column 2 of the Social Data Tables for 1998–2015 to calculate the population doubling time for these countries: your country, Canada, Chile, Finland, India, Zambia. [Canada (70/.6 = 116 years); Chile (70/1.1 = 64); Finland (70/.1 = 700) India (70/1.3 = 54); Zambia = (70/1.7 = 41)]
  4. Assume that your country has an average annual population growth rate of 1.8%. It will take 39 years for your country’s population to double. What changes will your country need to make to deal with this growth in population? Consider such issues as housing, health care, food supplies, transportation, employment, education, and the environment. Do you think your country presently has the resources to handle this rate of population growth? Why or why not? 

7. What consequences might a declining population growth rate have on a country’s economy and environment? [This depends on a number of variables including the use of technology and the level of demand for goods and services. Smaller populations may require fewer natural resources, but if demand remains high, or if the country is able to export its surplus production, there may be no significant decrease in overall environmental impact. Slower population growth might allow a country to implement environmental policies and develop the institutions which can help protect the environment. A smaller population may mean that there will be fewer workers, and thus fewer goods and services (unless technology helps to increase production).]

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