8. Measurement of population phenomena

Lessons 6 and 7 taught you about the content of population phenomena and the means for describing them. In this lesson you will learn how to calculate key ratios describing different population phenomena and see how they are examined in practice.

This lesson concerns one of the principal topics of this demography course, calculation of key ratios describing population phenomena. The lesson shows how key ratios are used to measure and examine population phenomena and in what way they guide conclusions made on population phenomena.

The numerous examples from actual statistical data of demography given in the lesson illustrate that population phenomena are diversified and long-span research subjects for statistics. You will find that the study of population phenomena consists of long-term monitoring that enables comparison of phenomena between decades, even centuries. The key ratios describing population phenomena can be used to make comparisons between different size populations - such as different countries. You will also see in what way population phenomena are connected to the general state of society, such as people's welfare and economic and political conditions of society.

In this lesson we also return to the concept of "risk population". You will learn more about this subject discussed in the previous lesson. You will understand how studies of population phenomena are guided by a population subject to a certain population change event and why in some cases these studies should concern only a specific and limited group.