Previous studies that suggested such a connection were often poorly designed, had dropout rates or did not control for factors that could affect the conclusion.
Considering human capital as a characteristic of the population, however, all four countries were advantaged by the large percentages of their populations who could read and write.
But even after taking these into account, people who were depressed turned out to be 17% more likely to develop diabetes than people who weren't depressed.
Given this unequal resource distribution, highland Incas needed access to the products of lower, warmer climatic zones in order to enlarge the variety and quantity of their foodstuffs.
And with the advent of so many technologies-true grayscale printing, latex ink technology, hybrid inks, multi-drop capabilities, etc. -it's instructive to consider a few perspectives.