Un metodo di stima degli intervalli genesici

Abstract

In order to calculate birth intervals it would be necessary to know the distribution of women by birth age, child birth orders and completed parity. As this peculiarity generally is not known, for the calculation of birth intervals we resort to the formulation of hypotheses on mean age of fertility at last child birth. In the recent fertility trend such hypotheses seem unsatisfactory as they lead, for some Tuscan birth cohorts of women, to evidently wrong estimation of birth intervals. Therefore we suggest a different procedure that permits, using ratios calculated by the data of the fertility table for which we want to measure birth intervals, to partition women with j children in two groups: those who have stopped their fertility and those who have carried on their fertility. Applied to the data of Tuscan birth cohorts of women, the method we suggest leads to satisfactory results apparently better than those obtained with other methods.