Do fertility transitions influence infant mortality declines? Evidence from early modern Germany

Abstract The timing and sequencing of fertility transitions and early-life mortalitydeclines in historical Western societies indicate that reductions in sibship (numberof siblings) may have contributed to improvements in infant health. Surprisingly,however, this demographic relationship has received little attention in empiricalresearch. We outline the difficulties associated with establishing the effect of sibshipon infant mortality and discuss the inherent bias associated with conventionalempirical approaches. We offer a solution that permits an empirical test of this relationshipwhile accounting for reverse causality and potential omitted variable bias.Our approach is illustrated by evaluating the causal impact of family size on infantmortality using genealogical data from 13 German parishes spanning the sixteenth,seventeenth, eighteenth, and nineteenth centuries. Overall, our findings do not supportthe hypothesis that declining fertility led to increased infant survival probabilitiesin historical populations.19 Halama