POPULATION REPRODUCTION - A METHOD OF BRE AKDOWN AND ESTIMATION

This article shows how, working with a number of loose hypotheses, a c lassic measure of reproduction R-0 can be broken down into a series of multiplicative components, each of which reflects a specific dimensio n (intensity or timing) of nuptiality, mortality, fertility and, if re quired, migration. This method can be used in two ways: - to obtain re latively complete data or estimates of demographic processes from, for example, a census or a status animarum where it is possible to apply the own-children method and to calculate the proportion of never-marri ed at different ages; - where these elements cannot be calculated, as, for example, when the data are obtained by nominal family reconstitut ion, it is preferable to use a slightly different method. This involve s estimating the mean number of female births to a generation of women subjected to mortality, migration and marriage. Multiplying this valu e by the duration of fertile marriage, gives an estimation of the tota l size of the female generation and thus of the value of R-0. A-number of simple algorithms are proposed for calculating the mean age at bir th and for estimating the proportion of women who are married at this age. An application to England. France and Germany establishes the exi stence and the characteristics of their respective demographic regimes in the XVIIth and XVIIIth centuries.