The main demographic revoulution in modern history has been the increased survival of children - the gradual elimination of the biological waste linked to the high mortality of the past. This volume examines the trends of early-age mortality across time and space and the methodological and theoretical problems inherent in such studies. It widens the discussion beyond the standard European focus by including data from Asian and American sources, showing that they offer enormous potential for researchers. At the same time, it makes clear the need for cautious treatment of historical data and points towards the design of techniques for appraising their quality, correcting distortions, and filling gaps. The analysis demonstrates that levels of infant and child mortality are linked not only to material conditions of life but also to social and cultural factors. The authors argue that a better understanding of these interactions can only come from an interdisciplinary approach, where demography joins forces with biology, medicine, public health, and social and economic history.