Socioeconomic differences and family clustering of infant and child mortality : a multilevel analysis of rural southern Sweden, 1766-1895

This paper focuses on how differences by socio-economic status, sex, and family unit in infant and child mortality developed during the first stage of the demographic transition. It uses multilevel Cox regression controlling for shared unobserved factors at the family level included to examine this issue. The problem of comparing the impact of unobserved factors at family level with the effects of observed factors is solved by employing a new method for converting the variation stemming from unobserved factors at family level into Median Hazard Ratio (MHR), directly comparable with relative risks. The data are for a rural area in Southern Sweden and comes from the Scanian Demographic Database. The principal findings are that while socioeconomic differences in child mortality widened and became much larger than sex differences by the end of the nineteenth century, differences between families belonging to the same socioeconomic group were even larger.