Final answer:
Population pyramids convey the age-sex structure, growth rate, and broader socio-economic implications of a population. They show distributions and trends that inform about birth rates, death rates, and migration patterns, and can signal demographic shifts such as the youth bulge.
Step-by-step explanation:
Population pyramids reveal three key aspects about a population: the age-sex distribution, the population growth rate, and insights into the social and economic structures. These graphical representations depict males and females in separate age cohorts and can indicate rapid growth, slow growth, or negative growth. A larger base of the pyramid suggests a higher number of young people, often indicative of higher birth rates, as seen in the population pyramid of Nigeria. Conversely, narrower bases, such as in many post-industrial countries, suggest lower birth rates and an aging population.
Analyzing a population pyramid helps to understand the demographic profile including the sex ratio and the distribution of different age groups within the population. Population pyramids also reflect changes over time due to various factors including births, deaths, and international migration. The youth bulge, for instance, is an example of a demographic trend with political and economic implications, especially regarding labor force participation and social stability.