Age and parity specific fertility intensities calculated from date of previous birth

José Antonio Ortega, Universidad de Salamanca

In the last years, methods for the analysis of fertility based on the age and parity fertility model have been proposed (Rallu-Toulemon; Kohler-Ortega). Data requirements for such analysis are, however, hard to fulfill, since the distribution of women by parity and age is seldom observed. A new method is introduced to calculate age-and-parity-specific fertility intensities based on questions regarding date of previous birth from civil registration microdata. Such data is available for a number of countries. The basic idea is to track births over time from cohorts of women defined by cohort, parity, and date of previous birth. This procedure has important advantages over currently used reconstruction procedures: the estimates are more reliable and stable than those based on sample surveys; and contrary to methods based on extrapolation from census, they do not deteriorate over time. The method is applied to fertility of Spanish nationals in the period 1980-2001.