This paper investigates the implications of an exogenous decline in mortality rates for capital accumulation and fertility in a neoclassical economy with dynastic preferences. The analysis shows that drops in mortality can explain the transition from a regime with high levels of fertility and low output per capita to a situation with low fertility and larger output per capita. The differential impact of mortality declines on different age-groups is shown to be very important in driving this result. A positive effect on per-capita output arises only if the reductions in mortality have a larger relative impact at young ages. The dynamic adjustment is consistent with the non-monotonic path of fertility over time observed over the demographic transition.
