1. What characteristics can make a population shrink or grow over time?
2. How can age structure diagrams be used to predict the future populations?
1. The population of a region can either shrink or grow over time depending on various characteristics. These characteristics include:
- Birth rates: High birth rates contribute to population growth, while low birth rates contribute to population decline. Factors that influence birth rates include access to contraception, cultural norms, and government policies.
- Death rates: High death rates can lead to population decline, while low death rates result in population growth. Factors that affect death rates include healthcare access, medical advancements, and overall quality of life.
- Migration: Influx of immigrants can lead to population growth, while emigration can result in population decline. Economic opportunities, political stability, and social factors often influence migration patterns.
- Fertility rate: Fertility rate refers to the average number of children born to women of childbearing age. High fertility rates can fuel population growth, while low fertility rates can lead to population decline.
- Life expectancy: Longer life expectancy generally contributes to population growth, as people live longer and contribute to the population for a greater period.
- Economic factors: Economic conditions, such as job opportunities and income levels, can influence population growth or decline. Strong economic growth often attracts people and leads to population growth, while economic decline can prompt migration and cause population shrinkage.
2. Age structure diagrams, also known as population pyramids, can be analyzed to predict future populations by examining the distribution of population among different age groups. This diagram typically displays the percentage or number of males and females in different age brackets.
Age structure diagrams provide insights into population growth, stability, or decline by highlighting the following:
- Youth dependency: A wide base in the pyramid indicates a larger proportion of younger individuals, suggesting a potential for future population growth.
- Reproductive age group: The middle sections of the pyramid represent the reproductive age group. Their size and distribution can provide cues about future birth rates and potential population growth.
- Elderly dependency: A higher proportion of older individuals towards the top of the pyramid indicates an aging population and potential population decline due to a smaller working-age population supporting a larger elderly population.
By analyzing the age structure diagram and considering factors such as birth rates, death rates, and migration patterns, demographers can make predictions about future population trends and plan accordingly for resource allocation, healthcare, and social policies.