Age-Period-Cohort Analysis

2

Why Cohort Analysis!

2.1 Introduction

Although studies of time-related change have long existed in the history of science, those that consider cohort change as distinct from age and time period variations appear in scholarly literature only relatively recently. Why is cohort analysis useful? Examples of the utility of cohort analysis can be found in demographic studies of human mortality. Descriptive analyses of nineteenth century English death rates clearly indicated stronger regularities in birth cohort changes relative to period variations (Derrick 1927; Kermack, McKendrick, and McKinlay 1934). The relevance of this approach was then recognized in subsequent epidemiologic investigations, the earliest of which is the well-known study ...