the birth rate falls more rapidly than the death rate or falls beyond a
certain point, it is evident that the normal growth of a nation is
hindered, and even its extinction may be threatened. While an
excessively high birth rate is a sign of low culture on the whole, on
the other hand an excessively low birth rate is a sign of physical and
probably moral degeneracy in the population. When the birth rate is
lower than the death rate in a given population, it is evident that the
population is on the way to extinction. In order that a birth rate be
normal, therefore, it must be sufficiently above the death rate to
provide for the normal growth of the population. On the whole, it seems
safe to conclude that we have no better index of the vitality of a
people, that is, of their capacity to survive, than the surplus of
births over deaths. Such a surplus of births over deaths is also a
fairly trustworthy index of the living conditions of a population,
because if the living conditions are poor, no matter how high the birth
rate may be, the death rate will be correspondingly high, and the
surplus of births over deaths, therefore, relatively low.

Vital statistics are, therefore, an indication of more than the mere
health or even the material condition of a given population. Probably
there are no social facts from which we may gather a clearer insight
into the social conditions of a given population than vital statistics.

Without going into the vital statistics of modern nations in any detail,
the following table of birth rates and death rates will serve to
illustrate the decrease in the death rates and the birth rates of the
three leading European nations, the birth rate being computed the same
as the death rate, that is, the number of births per thousand annually
of the population: