Reproduction and Longevity among the British Peerage: The Effect of Frailty and Health Selection

Gabriele Doblhammer, Max Planck Institute for Demographic Research
Jim Oeppen, Cambridge University

Among the female British Peerage we find a trade-off between the number of children and mortality after age 50. In the data this relationship is masked by two factors. First, by unobserved heterogeneity, which may partly be the result of mortality selection before age 50. Second, by frailty which influences both parity and late life mortality. Frail women may have fewer children and higher late life mortality while mothers of a large number of children most probably were less frail from their birth on and thus experience lower mortality. Due to these two confounding factors a simple survival analysis does not find a significant relationship between reproduction and longevity. The study is based on the British Peerage whose genealogies were established in 1962 by Hollingsworth. We use the birth cohorts of 1641 to 1850 which consist of 1854 females and 2202 males.