On the tempo and quantum

Dalkhat M. Ediev, Vienna Institute of Demography

This paper presents a general theory of the tempo and quantum of life events based on the notion of infinitesimally short life stages which successively cover the life span of every cohort. The tempo effect is shown to appear due to the different exposure of birth cohorts and the synthetic cohort to similar life stages. The distortions are neither linked to the type of events, cohort or period perspective nor to the type of rates describing the demographic process. The notion of postponement/anticipation of events is not a precondition for the tempo effect. We propose adjustment formulas for distortions at individual age groups, which correct such integral demographic indicators as the TFR when they are integrated over the life span. Our approach generalizes the results by Ryder, Bongaarts-Feeney and Kohler-Philipov without using their simplifying assumptions. The paper is supplemented by empirical example.