EFFECT OF MIGRATION ON INCREASE OF NEGRO 123 



sorbed into the blacks. The more capable and ambitious of the blacks, or 

 browns, who forge ahead and win a measure of success will probably con- 

 stitute a relatively sterile group. Differential mortality will of course take 

 its greater toll from the more improvident and less enlightened members of 

 the race, but it will probably not compensate for the dysgenic effect of the 

 differential birth rate. There will probably be a continual infusion of white 

 blood into the blacks which might be held to counteract their dysgenic 

 breeding, but this infusion is growing less in amount and probably poorer in 

 quality. 



Migration has apparently intensified the dysgenic breeding of our Negro 

 population. Up to at least recent years it has not led to the permanent 

 establishment of Negro communities in the north and west; that is, the 

 Negro communities thus formed have fallen short of self maintenance. 

 Whether the loss from a given section of a certain percentage of its popula- 

 tion, which goes into another region where it fails to reproduce itself, really 

 leads to a reduction of the rate of increase of the whole region is not imme- 

 diately evident. Taking out, say ten per cent of an increasing population, 

 might cause according to a principle enunciated by Malthus, the remaining 

 ninety per cent to reproduce more rapidly so as to produce nearly as many 

 people as before. At the same time the ten percent in the new region might 

 fall somewhat short of reproducing itself. If the region of increasing popu- 

 lation suffers a continual loss through migration, the total population might 

 grow more rapidly even though the migrants were not quite self per- 

 petuating. 



Possibly our Negro population may be in some such situation. With 

 our present statistical data it is impossible to tell. We do not yet have the 

 data needful for the calculation of stabilized rates of natural increase for 

 the census year 1930. We do know that for some time births have exceeded 

 deaths, but the highly favorable age composition of northern Negroes might 

 bring this condition about, although their stabilized rate of increase was 

 insufficient for maintenance. Hitherto northward migration has been a 

 march toward destruction. How nearly it may have come to be a success- 

 ful invasion we shall probably soon be able to discover. 



