Resumen:
Two seminal studies in the 1980s by Preston and Coale (1982) and Arthur and Vaupel (1984), generalized the Lotka equations using what later will become known as the variable-r methods. Comparisons across populations of sex ratios by age are studied under the perspective of the variable-r method to estimate fertility, mortality and net-migration contributions for changes in sex ratios by age. National age-specific female and male counts, used in the calculations of sex ratios by age, are decomposed into the birth counts, and the mortality and net-migration of each of the cohorts that they belong to. Thirteen countries with long historical demographic series are used to illustrate how sex ratio by age differs across populations, and how the cohort perspective contributes to those comparisons.
Biografía:
Vladimir Canudas-Romo es profesor y director de la Escuela de Demografía de la Universidad Nacional de Australia.
Registro al correo ebserna@colmex.mx