Methods for estimating cohort replacement effects

The author reexamines the hypothesis developed by Norman Ryder that the birth and death of individuals constitutes a massive process of personnel replacement that holds enormous potential for social change. "In this paper I describe and illustrate six possible ways to estimate cohort (personnel) replacement effects: three based on algebra (Kitagawa's two-component method, forward partitioning, and backward partitioning), and three based on regression (regression standardization, survey metric analysis, and linear decomposition). Assuming monotonic change, regression methods typically are better, because standard algebraic methods are ill suited for analyzing change with regard to birth cohorts that enter or exit during the period studied."