""You usually have a proportionately higher birthrate in lower income populations. This is true all over the world, not just in Mexico. When people become more affluent, the birthrate declines.""

Unless of course the country in question is hag ridden by Catholic clergy, and denied the means of effective birth control by an omnipotent cleric who has no idea what effect unbridled breeding can have on a population deprived of the food, water, and industry necessary to an exploding population.

That's the true reason for this population increase, much as it may discomfit the "Christians", so called, of the USA.

Don T.