The deleterious effects of rapid childbearing on infant and early child survival chances have been the subject of study for at least 60 years. Indeed, 1923 saw the publication of two of the earliest known studies in this area. One was the little-known analysis by Stevenson (1923) using results from questions on children ever born and children surviving in the 1911 population census of England and Wales. To this day, this must be the largest single study bearing on the issue of child-spacing effects on mortality of the children. Stevenson examined proportions of children surviving by number of children ever born, duration of marriage, and age at marriage of the mother. Although there are some methodological problems with Stevenson’s approach, his discussion is quite perceptive and concludes that an optimal average birth interval for child survival is between 2 ½and 3 years.