Edwin Cannan was an English economist whose many publications included some material on population, almost all of which is still considered important. Cannan spent his entire working life at the London School of Economics, joining the teaching staff of that school at its foundation in 1895, becoming a professor of political economy in 1907, and retiring in 1926.
Cannan is credited with developing the notion of an optimum population. He rejected the Malthusian argument that there is an inherent tendency toward overpopulation. In his first book, Elementary Political Economy (1888), Cannan wrote: "[P]roductiveness of industry is sometimes promoted by an increase of population, and sometimes by a decrease" (p. 22). He believed that in a specific area of land a definable amount of labor is required for the maximum productiveness that is possible. He subsequently elaborated those ideas, especially in Wealth (1914, 3rd ed. 1928), and used the expression optimum population. The optimum may rise or fall with changes in knowledge or capital, but in practical and moral terms any resulting policy (which in principle should recognize the interests of future generations) can only specify a direction of movement at any particular time.
The Economic Journal for December 1895 included Cannan's "The Probability of a Cessation of the Growth of Population in England and Wales during the Next Century." That article presented the first cohort-component population projection, in which each age group is dealt with separately, and births, deaths, and migration are taken into account separately. His projection assumed the same number of births each ten years as had occurred in the period 1881–1890 (and thus a declining rate of childbearing) and the same proportionate losses at each age as a result of mortality and emigration combined as was observed between the 1881 and 1891 censuses.
Cannan correctly predicted, against contemporary opinion, the continuation of the decline in the birthrate in Britain that had begun recently. This was a remarkable achievement. As John Hajnal commented in a paper presented at the 1954 World Population Conference, Cannan "could publish 36 years later, in 1931, a paper which said in effect 'I told you so"' (p. 46). Even though, as Hajnal noted, "the accuracy of his forecast was not outstanding…[and] by 1911, i.e., only 15 years after the forecast was made, the population enumerated at the census exceeded the prediction by 7 per cent and by 1916 the population had increased beyond his estimate of the maximum it would ever reach…. Cannan's forecast, though inaccurate, predicted an unexpected development by acute analysis"(pp. 46–47, 48).
Cannan later became aware that the birthrate had declined in other Western countries and in Economic Scares (1933), perhaps 40 or 50 years before this became empirically incontrovertible, declared that "the cause of it–birth control–will doubtless in time affect the rest of the world" (p. 92). He foresaw also, though, that for many years non-Western countries would experience considerable and even enhanced population growth "owing to decrease of huge infant mortality."
selected works by edwin cannan.
Cannan, Edwin. 1888. Elementary Political Economy. London: H. Frowde.
——. 1895. "The Probability of a Cessation of the Growth of Population in England and Wales during the Next Century." Economic Journal 5:505–515.
——. 1914. Wealth. London: P. S. King.
——. 1933. Economic Scares. London: P. S. King.
——. 1997. Collected Works, 8 vols., ed. Alan Ebenstein. London: Routledge/Thoemmes Press.
selected works about edward cannan.
De Gans, Henk A. 1999. Population Forecasting 1895–1945. Dordrecht, the Netherlands: Kluwer Academic Publishers.
Hajnal, John. 1955. "The Prospect for Population Forecasts." Proceedings of the World Population Conference 3: 43–53.
Robbins, Lionel. 1927. "The Optimum Theory of Population." In London Essays in Economics: In Honour of Edwin Cannan, ed. Theodor E. Gregory and Hugh Dalton. London: Routledge.
C. M. Langford