Edwin Chadwick and the poverty of statistics

In his 1842 Report on the sanitary condition of the labouring population of Great Britain, Edwin Chadwick demonstrated the existence of a mass of preventable illness and premature death in the community caused, he argued, by insanitary physical circumstances.'Although much of the evidence for the existence of this preventable mortality was anecdotal, Chadwick included a chapter of differential class-based death data which dramatically illustrated the extent to which insanitary physical circumstances shortened life.Chadwick's chosen statistical measure-the average age at which a given class of people died showed that what he called the "average period of life" or "chance of life" was as low as 17 for labourers in Manchester but as high as 52 for gentry in Rutlandshire.2Although his statistics were widely quoted at the time,3 professional statisticians dismissed the data and historians ever since have paid little serious attention to it.4In this paper I will argue that Chadwick's class-based average-age-at-death data were a central feature of the Sanitary report and that we cannot fully appreciate the argument or even the organization of the report without them.