Free Why Nations Fail: The Origins of Power, Prosperity, and Poverty by Daron Acemoğlu, James Robinson Page B

Tropic of Capricorn, which today include Mexico, Central America, Peru, and Bolivia, held the great Aztec and Inca civilizations. These empires were politically centralized and complex, built roads, and provided famine relief. The Aztecs had both money and writing, and the Incas, even though they lacked both these two key technologies, recorded vast amounts of information on knotted ropes called quipus. In sharp contrast, at the time of the Aztecs and Incas, the north and south of the area inhabited by the Aztecs and Incas, which today includes the United States, Canada, Argentina, and Chile, were mostly inhabited by Stone Age civilizations lacking these technologies. The tropics in the Americas were thus much richer than the temperate zones, suggesting that the “obvious fact” of tropical poverty is neither obvious nor a fact. Instead, the greater riches in the United States and Canada represent a stark reversal of fortune relative to what was there when the Europeans arrived.
    This reversal clearly had nothing to do with geography and, as we have already seen, something to do with the way these areas were colonized. This reversal was not confined to the Americas. People in South Asia, especially the Indian subcontinent, and in China were more prosperous than those in many other parts of Asia and certainly more than the peoples inhabiting Australia and New Zealand. This, too, was reversed, with South Korea, Singapore, and Japan emerging as the richest nations in Asia, and Australia and New Zealand surpassing almost all of Asia in terms of prosperity. Even within sub-Saharan Africa there was a similar reversal. More recently, before the start of intense European contact with Africa, the southern Africa region was the most sparsely settled and the farthest from having developed states with any kind of control over their territories. Yet South Africa is now one of the most prosperous nations in sub-Saharan Africa. Further back in history we again see much prosperity in the tropics; some of the great premodern civilizations, such as Angkor in modern Cambodia, Vijayanagara in southern India, and Aksum in Ethiopia,flourished in the tropics, as did the great Indus Valley civilizations of Mohenjo Daro and Harappa in modern Pakistan. History thus leaves little doubt that there is no simple connection between a tropical location and economic success.
    Tropical diseases obviously cause much suffering and high rates of infant mortality in Africa, but they are not the reason Africa is poor. Disease is largely a consequence of poverty and of governments being unable or unwilling to undertake the public health measures necessary to eradicate them. England in the nineteenth century was also a very unhealthy place, but the government gradually invested in clean water, in the proper treatment of sewage and effluent, and, eventually, in an effective health service. Improved health and life expectancy were not the cause of England’s economic success but one of the fruits of its previous political and economic changes. The same is true for Nogales, Arizona.
    The other part of the geography hypothesis is that the tropics are poor because tropical agriculture is intrinsically unproductive. Tropical soils are thin and unable to maintain nutrients, the argument goes, and emphasizes how quickly these soils are eroded by torrential rains. There certainly is some merit in this argument, but as we’ll show, the prime determinant of why agricultural productivity—agricultural output per acre—is so low in many poor countries, particularly in sub-Saharan Africa, has little to do with soil quality. Rather, it is a consequence of the ownership structure of the land and the incentives that are created for farmers by the governments and institutions under which they live. We will also show that world inequality cannot be explained by differences in agricultural productivity. The great inequality of the modern world that emerged in the nineteenth