Published online by Cambridge University Press: 07 November 2014
During the last fifteen years carefully prepared population forecasts have appeared for nearly every important country possessed of reasonably adequate vital statistics and census records. With the general recognition of essential differences between the behaviour of bugs in a bottle and homo sapiens “in leaky national containers”, the usual procedure in the more recent studies has been to isolate the principal component factors in population growth, predict the future trend in each, and thus estimate the probable population ten, twenty, fifty, or more years hence. Already the majority of even the more conservative forecasts are proving too high and almost invariably because of over-estimation of the birth-rate.
Errors of this sort are not unexpected in view of the inherent difficulties of the problem. Their number is legion; it will suffice to note three. First, there is the difficulty of foreseeing changes in the social and particularly in the economic environment. Even in so-called normal times, each year brings unanticipated and sometimes substantial modifications in the complex of social forces making for greater or smaller rates of population increase. The duration and severity of such abnormal phenomena as the present depression are, of course, incapable of measurement in advance. Second, the nature and extent of human reactions to environmental change vary greatly both from country to country and from time to time. How a particular people will behave in a new situation is, therefore, usually a matter of considerable uncertainty. This uncertainty is in part at least attributable to a third difficulty. While many excellent studies, especially during the last decade, have contributed materially to a more adequate understanding of the forces controlling population growth, the existing state of knowledge still falls appreciably short of permitting precise quantitative measurement of many important influences on the birth-rate.
1 For example, see Thompson, Warren S. and Whelpton, P. K., Population Trends in the United States (New York, 1933).Google Scholar
2 Theoretically it would have been slightly more correct to have based the calculations on the age distribution of women two and a half years prior to each census date (i.e., at the middle of the period in which the children 0-4 were born). The error, however, is negligible. It should be kept in mind that no allowance is made here for difference in the proportions married.
3 This compares with an estimated drop of 40.0 per cent, between the five-year averages 1875-9 and 1925-9 in the United States. See Thompson and Whelpton, Population Trends in the United States.
4 Mr. M. C. MacLean of the Dominion Bureau of Statistics suggests that since the decade preceding 1901 was marked by unusually heavy emigration of single females of child-bearing age to the United States, the real drop in the birth-rate in the years immediately preceding the turn of the century was appreciably higher than these figures suggest. The past six decades appear to have included two distinct cycles in the birth-rate.
5 I find that volume I of the 1931 Census when published, is to include historical tables showing marital condition by sex for the early decades. The proportions of the female population (15 and over) married appear to have shown only minor fluctuations prior to and including 1921.
6 This procedure is based on the assumption that a change in the general age distribution of women does not in itself affect the proportions of women in the individual age categories who are married,—in other words, that they are independent variables. It is believed on a priori grounds that this assumption is substantially correct and that the method of simple subtraction is here justifiable. Both sets of percentages are, of course, only approximations because the specific rates used in each case are functions, not only of age and marital condition, but to some extent of the varying incidence of residual factors such as birth control, illegitimacy, etc., at the different ages.
7 For method of computation see Hurd, W. B. and Cameron, J. C., “Population Movements in Canada 1921-31: Some Further Considerations” (Canadian Journal of Economics and Political Science, vol. I, no. 2, 05, 1935).Google Scholar
8 In the older Eastern Provinces the change in age distribution was much less marked than in the West. Those provinces were settled much earlier and their age distribution was not so severely distorted by heavy immigration during the first two decades of the century. Quebec, which on balance was least affected by current female immigration and emigration registered no change. Ontario had shared more heavily than other Eastern Provinces in pre-war immigration and a moderate corrective movement was recorded despite an appreciable excess of net immigration (from other provinces and abroad) over net emigration of native-born. The situation in the Maritimes was peculiar. They suffered through emigration to a far greater extent than did any other section of Canada, yet on the whole the age distribution of resident females of child-bearing years was not more seriously affected than was that of Ontario. The large declines in Manitoba constituted a normal re-adjustment from the unusually favourable age distribution in 1921 produced by the heavy influx of settlers during the preceding two decades. It was accentuated by moderate emigration of women which was especially heavy in age categories where birth-rates are highest. The larger decline in Saskatchewan represents a proportionate reaction from an even more abnormal age distribution in 1921. In Alberta and British Columbia net immigration from abroad and other parts of Canada in excess of net emigration of native residents of the province to some extent offset the general ageing of the female population as a whole and reduced potentially large declines to amounts much lower than obtained in the other two provinces of the West.
9 Marriages in seven provinces for which complete data covering the period are available were as follows:
New Brunswick and British Columbia are not included in the above totals. Average yearly births, 1914-8, numbered 56,155. Between 1919 and 1921 the average was 67,298. These figures compare with an average of 61,226 for the years 1911-3, a period of great prosperity in Canada.
10 This seems to be an appropriate place to discuss the effects of the War on the number of children 0-4 in 1921. These children were born between June, 1916, and June, 1921, a period including three years when the birth-rate was considerably depressed because of the absence of husbands and two years of abnormally high rates owing to their return after the War and to the contraction of large numbers of delayed marriages. An examination of the trend in births in the various provinces indicates that the post-war surplus just about offset the deficiency in the previous three years, so that the number of children 0-4 in 1921 appears to have been about in accordance with normal expectation. The number certainly was not higher than expectation; as in the case of the proportion married it might have been slightly lower. The ratio of such children to women of child-bearing age and the decline in the crude ratio (14.4 per cent.) would, therefore, appear to have been relatively uninfluenced by transient causes.
11 The association between the birth-rate and rural and urban residence is set forth in the following table:
The technique used in making the above corrections is similar to that described in earlier sections of the study. It is seen that the birth-rate as measured by the ratio of children 0-4 to women 15-44 was 24 per cent. higher in rural parts, and 20 per cent. lower in urban than in the population as a whole, and that, after allowance had been made for differences in age distribution and conjugal condition of women of child-bearing age. The larger the urban centre (other things being equal) the lower the birth-rate. In cities 30,000 and over the rate was 30 per cent, below that for all Canada. Rural birth-rates appear to be about 45 per cent. higher than urban rates generally.
Figures for individual races tell the same story. The rates for the English and French, the two most numerous stocks in Canada, appear below. These data are corrected for differences in age distribution but not for conjugal condition.
12 Another factor making for more favourable conjugal condition is an increase in the surplus of males in the population. This tends naturally to intensify the competition for eligible females of marriageable age. The excess of adult males per 100 adult females in the population increased only from 11 to 12 between 1921 and 1931. The effect of so small a change can hardly be significant.
13 See footnote 8.
14 While the arresting of rural-urban migration, which in the past has contained a somewhat disproportionate share of single females, might be expected to restore greater equality of the sexes in rural parts and hence stimulate marriage, it seems very unlikely that the latter result will materialize under anything approaching current depressed conditions in rural areas. If and when conditions permit it is logical to assume that females will again be prominent in such city-ward movement as may develop.
15 Other factors include changes in infant mortality and in the number of first births. It was pointed out in an early part of this study that no significant change occurred during the decade in the death-rate among infants and young children. A bride just turned 22 is more likely to give birth to a child than a woman of 22 years who has been married for some years. The marriage rate thus not only affects the conjugal condition and age distribution of married women, for which allowance has been made in column 6, but in addition directly influences the birth-rate to a greater or less degree. There seems to be no method of making allowance for this factor since existing data do not carry back to 1921. Its influence, however, should be mentioned.
16 See Kopp, M. E., Birth Control in Practice (New York, 1934)Google Scholar; Pearl, Raymond, “Contraception and Fertility in 4,945 Married Women” (Human Biology, vol. VI, no. 2)Google Scholar; etc.