Page:Popular Science Monthly Volume 67.djvu/768

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Bureau of the Census has issued a bulletin on the proportion of children in the United States, containing valuable statistics secured at the last census and a discussion by Professor Walter F. Willcox, of Cornell University. There is unfortunately verv little exact knowledge concerning the birth rate or the size of families in the United States; but in some ways the proportion of children to the total population or to the number of women of child-bearing age is more significant than the birth rate. The birth rate, which is usually given as the number of births each year per thousand population, is only significant when taken in connection with the death rate. The birth rate has been steadily decreasing in all civilized countries, and most rapidly in the countries that are regarded as the most civilized, but at the same time the death rate has been decreasing nearly in same proportion, so that the increase of population per thousand inhabitants has remained nearly stationary in recent decades. But these, figures require further analysis. In so far as the decreased death rate is due to the saving of the lives of healthy infants, it can to real advantage supplement the decreasing birth rate. In so far, however, as the decreasing death rate is due to the prolongation of life beyond the age at which children are likely to be born, or in so far as it is due to saving the lives of children who are constitutionally feeble, the result in the next generation will be a sharp decline in the birth rate without any further decrease in the death rate. The size of family again is not significant unless taken in connection with the number of children that survive and the proportion of people who are married.

The number of children under five years of age compared with the number of women from fifteen to forty-nine years of age is given in the census,

and these figures are perhaps as simple and convenient as any for the study of changes in the fertility of the population. They should, however, be correlated with the birth rate and death rate and the size of family, and require further analysis, immigration and alteration in the frequency of death at different ages being complicating factors. The bulletin shows that at the beginning of the nineteenth century the children under 10 years of age constituted one third and at the end less than one fourth of the total population. The decrease in this proportion began as early as the decade 1810 to 1820, and continued uninterruptedly, though at varying rates, in each successive decade. This of itself, however, is not enough to prove a declining birth rate, as the decrease in the proportion of children in the total population may indicate merely an increase in the average duration of life and the consequent survival of a larger number of adults.

But by taking the proportion of children to women of child-bearing age we are able to get a more satisfactory index of the movement of the birth rate. Between 1850 and 1860, the earliest decade for which figures can be obtained, this proportion increased. But since 1860 it has decreased without interruption. The decrease has been very unequal from decade to decade, but if twenty-year periods are considered, it has been very regular. In 1860 the number of children under 5 years of age to 1,000 women 15 to 49 years of age was 634; in 1900 it was only 474. In other words, the proportion of children to potential mothers in 1900 was only three fourths as large as in 1860. One is thus led to the conclusion that there has been a persistent decline in the birth rate since 1860.

A comparison is made between the proportion of children born of native mothers to 1,000 native women of child-bearing age and the proportion of children born of foreign-born mothers