The Economic Basis of the Empire: The Principle of Population
There are very few countries in which one does not observe a constant pressure of the population toward an increase beyond the means of subsistence.
-- Malthus, An Essay on the Principle of Population
Rarely does a country offer a more beautiful illustration of Malthus' law than the empire of the Incas. The increase of population in relation to the means of subsistence was one of the dominant factors in the imperial policy; and the conquests, the technical progress, the social organization all expressed the continuous effort of the Quechuas to extend and intensify the cultivation of the soil.
To be sure, vital statistics are lacking, not because they are nonexistent -- on the contrary, the gathering of statistics had attained a rare degree of perfection, as we shall see -- but because we no longer know how to read the quipus by which they were recorded. Nevertheless, the increase in population before the Spanish conquest is evident not only from the statements of the chroniclers, but from a study of the facts. Ondegardo declares that the number of native inhabitants had increased "in a marvelous man-