The verification of data in historical demography

Abstract In all scientific studies care must be taken to work on data which are correct and hence to make sure of the quality of the observations. In the field of historical demography there is need for extra care. The data were collected a long time ago in circumstances which were sometimes good, sometimes bad, but often little known. Statisticians are, moreover, on a priori grounds, rather inclined to be more suspicious of observations made in the past than of those which are made currently. Results relating to past populations must therefore be more rigorously established than any others if they are to be accepted. The verification of the data thus forms an integral part of the work of the historical demographer.