Abstract
This paper investigates the effects of malaria control programmes on mortality and fertility rates, and hence on population growth, with special reference to Ceylon. The crude death rate (C.D.R.) by district in Ceylon fell sharply from pre‐1945 to post‐1945 on the average, and the variance between district C.D.R.s almost disappeared; it is shown that the near‐eradication of malaria can account wholly for the latter phenomenon but not completely for the former, more than half of which was due to causes other than changes in malaria prevalence. Crude birth rates (C.B.R.s) by district rose moderately on the average from pre‐1945 to post‐1945, and substantially increased their variance. It is shown that the near‐eradication of malaria is consistent with the latter phenomenon, but that even in the absence of malaria control the national C.B.R. would have fallen slightly, as it has done in recent years. A technique is devised by means of which it is possible to establish that these shifts in district C.D.R.S and C.B.R.s, in the decade or so following the war, were due mainly to changes in district age‐specific vital rates rather than to changes in age distributions brought about by past fertility rates or by internal migration. The paper closes with a brief discussion of other studies of this set of problems.