<Dl> <Dt> "Expansive" pyramid </Dt> <Dd> A population pyramid that is very wide at the younger ages, characteristic of countries with high birth rate and low life expectancy . The population is said to be fast - growing, and the size of each birth cohort gets larger than the size of the previous year . </Dd> </Dl> <Dt> "Expansive" pyramid </Dt> <Dd> A population pyramid that is very wide at the younger ages, characteristic of countries with high birth rate and low life expectancy . The population is said to be fast - growing, and the size of each birth cohort gets larger than the size of the previous year . </Dd> <Dl> <Dt> "Constrictive" pyramid </Dt> <Dd> A population pyramid that is narrowed at the bottom . The population is generally older on average, as the country has long life expectancy, a low death rate, but also a low birth rate . However, the percentage of younger population are extremely low, this can cause issues with dependency ratio of the population . This pyramid is more common when immigrants are factored out . This is a typical pattern for a very developed country, a high level of education, easy access to and incentive to use birth control, good health care, and few negative environmental factors . </Dd> <Dd> </Dd> <Dd> </Dd> </Dl>

What does a wide base on a population pyramid indicate
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