Blackwell Reference Online

Extract

Demographers are often interested in comparing rates (e.g., birth rates, mortality rates) in populations cross-nationally and/or over time. Interpreting difference between rates requires an understanding of the various factors that comprise that rate. Crude birth rates, for example, depend not just on the fertility of women of childbearing age, but also the proportion of the population that consists of such women. In such cases, in which the overall rate of a phenomenon for a population depends on a number of factors, a detailed comparison of two such rates from two different populations can be made in two distinctly different but closely related ways. One way is to see how the overall rates would change if one of the factors varied as it did in the two populations, while the other factors were kept at the same levels. The rates obtained in this way are called the standardized rates with respect to the unchanged factors, and the process is called standardization . The other way of comparing the two overall rates is to break the difference between these two rates into additive components constituting the effects of the factors involved. The effects of the factors obtained in this way are called the decomposed effects and the process is called decomposition . These two processes of standardization and decomposition are closely linked because, if they are developed correctly, the ... log in or subscribe to read full text