Tempo-quantum and period-cohort interplay in fertility changes in Europe

Using detailed data on period and cohort fertility in four European countries, this paper discusses various indicators of period fertility, including indicators adjusted for changes in fertility timing. Empirical analysis focuses on the comparison of cohort fertility and corresponding indicators of period fertility; particular attention is paid to the periods of intensive postponement of childbearing. Some period indicators come consistently closer to the completed cohort fertility than the total fertility rates. This pattern of differential period-cohort approximation widely varies by birth order. Quite high level of approximation is provided by the tempo-adjusted birth probabilities of parity 1 and a combined indicator of total fertility. Two examples illustrate the use of indicators discussed in the paper: the first provides an estimation of the tempo (timing) and quantum (level) components in fertility change in the Czech Republic and the second presents projections of cohort fertility in the Czech Republic and Italy.