Almost 30 years have passed since I introduced the concept of “net intergenerational wealth flows” in a PDR essay, “Toward a restatement of demographic transition theory.” A great deal of research has been published since then, and accordingly an update is needed. That research suggests the following propositions. Immediately before fertility transition, children's farm labor may not quite offset their consumption, although much depends on how far into adulthood they continue to perform at least some work for their parents. In premodern times children may have paid their way because of lower consumption. Research on the pre-transitional value of children's work produced contradictory results because it examined both hunter-gatherer societies, in which both adults and children worked comparatively few hours, and farming societies, in which both worked longer hours. In pre-transitional societies, the insurance value of children was almost unlimited. For most people in most societies, alternative ways of maintaining savings from the earlier to the later stage of the life cycle first became available only when large-scale investment in children's education was possible. The costs and gains from that investment played a major role in the onset of the fertility transition.