Population statistics and their compilation

A considerable number of major developments have occurred in the theoretical and practical problems involved in the compilation of population statistics since this book was first published under its present title, as "Actuarial Study No. 3," by the Actuarial Society of America in 1925. This new edition accordingly has been re-written and enlarged through out, in order to incorporate the necessary descriptions and references covering that new material.
In Section II the history of census-taking has been dealt with more fully in the light of various papers which have appeared since 1925, and the details concerning modern censuses have been brought up to date. Similarly the discussion of registrations of births, deaths, and marriages in Section III includes recent contributions, Section IV, on the reliability of census and registration statistics and the nature of the errors therein, also now gives data which have become available for various countries. since publication of the first edition, and the extent of under-enumeration and under-registration is considered. In Section V emphasis is given to the importance of preliminary adjustments for errors of age under some circumstances, and the treatment of population estimates includes an examination of the elusive problem of projections.
Section VI, dealing with the mathematical relationships between births, deaths, and populations, and the resulting formulae for the rates of mortality, now includes formula (180) devised by Moriyama and Greville, and has been enlarged with additional explanations and proofs. This latter material has been brought in to emphasize the importance of the device by which the assumptions of uniform distributions can be stated in terms of probabilities, and to direct attention more effectively to the very easy and rapid manner in which the mortality formulae based on the uniformity assumptions can be reached by the use of a simple Lemma-both of which methods were first stated in my paper in T.A.S.A., XXIV, 126, from which the explanations have been taken.