Critical Questions for Ageing Societies. Carney, Gemma

in different countries, regions or time periods are ageing.

Population pyramids

      Every academic discipline has its signature device that draws in new scholars and keeps those already engaged interested for years, decades, and even lifetimes. Geographers have maps, economists have supply and demand curves, historians have archives and demographers have population pyramids. As demography is the study of the changing structure of human populations, the use of population pyramids has filtered into general use by gerontologists (scholars of ageing). Indeed, population pyramids are so integral to understanding and explaining population change that we have provided the tools for you to create your own population pyramid at the end of this chapter.

       What are population pyramids?

      Population pyramids are a simple graphical device for demonstrating how many people are alive at a particular period of time in a certain location. A basic population pyramid like the one shown in Figure 1.1 has the number of people on the horizontal x-axis and age cohorts on the vertical y-axis.

      Pyramids are generally colour-coded into male and female divisions. There are some websites which allow you to surf different population pyramids by country and region (see https://populationpyramid.net). If you play around with these you will find some fascinating (and sometimes alarming) differences between the gender and age balance of different populations around the globe. For instance, a population pyramid from the US in 1950 will show a high birth rate, as indicated by the wide base on the x-axis. If you change the year to 2010 you will see major changes at the top and the base of the pyramid. Now there are some 60,000 people living in the US reaching the age of 100 or more. In 1950, the highest age bracket recorded on the pyramid was 80+. This means that while some of those living in the US might have survived up to 100 and beyond at that time, they were so few in number that they could not be recorded meaningfully on the pyramid.

Figure 1.1: An illustrative population pyramid

      Population pyramids are also really useful for helping us to understand why some countries can be viewed as ‘old’ countries while other countries still report themselves as having ‘relatively young populations’. Once you have mastered the art of deciphering population pyramids you will be able to check out these facts for yourself. Population pyramids also help us to understand the relationships between different birth cohorts, the overall balance of the population and the ratio of young people to old people. These figures are important as they are used by policy analysts and economists to calculate something called ‘the dependency ratio’, which we will explain in more detail in Chapter 3. For now, take some time to learn how to read a population pyramid, create your own population pyramid, and compare and contrast population pyramids across the globe.

      Of course, population pyramids are only one way of demonstrating what a population structure looks like. There are many other methodologies available to researchers of ageing societies. For instance, evolutionary biologists (scientists who study the development of the human race) have a hypothesis that humans have evolved to live beyond the age of sexual reproduction because our ancestors worked out a way to make themselves useful. The detail of the theory is that grandmothers found ways of helping their adult daughters to take care of their offspring (Hawkes, 2003). This adaptation meant that there was a purpose for older members of the tribe and humans began to live longer. Of course, as scholars of ageing we are interested in human ageing in the present day. In particular, we are fascinated in the implications that having an older population may have for social policy. We are also interested in how the experience of ageing may differ from country to country and from region to region. All of these issues will be explored in subsequent chapters.

A final thought

      In this chapter we have tried to whet your appetite for investigating what it means to live in an ageing world. We have introduced some of the most important elements of research infrastructure, tools and methodologies that researchers use to explore and understand population ageing. To do this, we have given detailed examples and instructions on how to construct and interpret a population pyramid. We have explained the main drivers of population ageing and how they produce a higher average age in the population. We have made some important detours into critical thinking by asking you to consider when old age begins and to begin to tackle the perennial problem of differentiating myths from facts about our ageing world.

      So, we hope by now you are convinced by the United Nations (2002) claim that population ageing is worth studying because it is ‘pervasive, enduring’ and has ‘profound implications’.

REVIEW EXERCISE 1

      Creating a population pyramid. See Appendix 1 for detailed instructions.