Population momentum as a measure of ageing.

"This paper aims to show that the concept of population momentum clarifies the nature of the process of population ageing and provides a basis for comparative research through time and between countries. The paper discusses the role of momentum in age-structure change during the demographic transition and examines trends in total and age-specific momentum in nine countries with contrasting patterns of transition. The utility of the concept of momentum in the demographic study of ageing arises from its focus on cohort flow, from the insight it provides into the causes and consequences of ageing and from its ability to identify variations in the process through time." (SUMMARY IN FRE)