Problem Set 1
1. Population Pyramid
a. (See attached page for population pyramids and sources.)
b. Consider the changes in each country’s pyramids over time.
1. Both pyramids are characteristic of population pyramids of less developed countries,
widening out at the base, which indicates that young people are a very large share of the
population. However, very young children (0-4) make up a smaller percentage of the total
population in 2012 than in 1970, and in general, it can be seen that the population as a
whole is aging slightly.
2. Although the effect is very small, the population has aged slightly. A population can
become older as a whole if fertility is decreasing or because mortality has decreased,
leading to the “survival effect”. The change in shape suggests than a decrease in fertility
rates is likely in Angola between 1970 and 2012.
1. The 2012 population pyramid is characteristic of a developed country, while the 1970
pyramid suggests that Brazil was a less developed country at the time. The population as
a whole was much younger in 1970 (young people/children made up a larger share of the
population). In 2012, the pyramid is rounder and the population has aged. The population
is shrinking because the percent of the population that is very young (0 to 4) is smaller
than older children.
2. The pyramid suggests that fertility rates have fallen greatly in recent decades, since the
population is contracting at the base.
ANGOLA VS BRAZIL:
1. The pyramids by themselves do not tell us which country has a larger population size,
because the values are all given as a percent of the total population of each respective
2. There is no way to tell if any country had a below-replacement rate fertility rate in 2012.
In Brazil, the percent of the population that was 0 to 4 years old was less than the percent
of 5 to 10 year olds, indicating that fewer children were born in recent years. In turn, the
share of 5 to 10 year olds is smaller than the share of 11 to 14 year olds. Clearly, fertility
is decreasing. However, we can’t tell if fertility has reaches below-replacement levels
because for that we would have to know the number of children born per women. Since
the reproductive ages of women span multiple age groups, we can’t figure this out from
the population pyramid. 3. Brazil has changed from a population pyramid with a wide base that was very typical for
“least developed” nations to that of a modern “more developed” nation rapidly. While
Angola’s pyramid has also changed from