The Effect of Changes in Mortality Rates on Population Growth and Age Distribution in the United States

The effects of changes in mortality rates on a population's growth and age composition depend on a number of factors: the initial level of mortality, the magnitude and age pattern of the mortality changes and the levels of fertility prior to and subsequent to the changes. The variety of effects associated with variations in these factors has been studied analytically as well as empirically.l5 In this paper the empirical approach will be stressed, the focus being on the role of mortality in the development of the United States population in the twentieth century.6 Three key generalizations have emerged from viewing the problem analytically. These will prove useful in studying the United States data and the data in turn will serve to illustrate and amplify these points.