THE DECLINING BIRTH RATE. 357 



United States, and even in Massachusetts, the population as a whole 

 is increasing, but the increase is confined for the most part apparently 

 to the immigrating classes. Inasmuch as the failure to increase is 

 confined to only a part of the population in the United States, it is 

 extremely difficult to ascertain the exact situation by statistical means. 

 An insidious loss may be going on in a particular direction and still 

 be undiscovered because of defective mortality statistics. 



These statistics put the whole native population of Massachusetts 

 in the same position as college graduates, and the question accordingly 

 seems to be one of the upper class or of the older part of the population 

 and not simply a question of the educated classes. 



In the absence of further statistics upon the subject, it will be of 

 assistance to ascertain, by theoretical law if possible, the causes which 

 contribute to these suicidal tendencies in the population. Laws of 

 population have been formulated from similar experiences in other 

 countries, and among these laws we may find one which will throw 

 light upon our own situation. 



It will not be worth while to review the common theories of popu- 

 lation and show their application to our present conditions. The 

 theory of Malthus, or even that of Spencer, will be of littl^ avail, as the 

 birth rate in the United States is not greatly afEected by physical causes. 

 And, although some writers have pointed to a possible biological cause, 

 it is improbable that in a new country like the United States even the 

 older part of the population could, as a class, be losing its fertility, 

 when in so many of the older countries the fertility of the population 

 is still good. 



To social causes, primarily, are due the differences in the fecundity 

 of civilized peoples. Therefore I shall present what may be called a 

 social law of population. From the nature of the case any law of 

 population must be exceedingly general, because a great number of 

 conditions directly or indirectly affect the birth rate, and these second- 

 ary causes differ in different localities. The law which I am about to 

 consider explains the situation only in a general way. Some of the 

 special conditions which affect the birth rate here I shall discuss later 

 on. This law of population is one formulated by a French student of 

 demography, Arsene Dumont. In brief M. Dumont's theory is that 

 population increases inversely with 'social capillarity.' This expressive 

 phrase is almost self-explanatory. Among progressive peoples a strong 

 tendency exists for men to improve their condition, and in a democratic 

 country society yields somewhat to efforts in this line. If competition 

 is severe it will be necessary for men to make a great effort to raise their 

 standard of living, or sometimes, even to maintain the accustomed 

 standard. Population is regulated by the intensity of the effort made. 



