But in several crucial ways, geography has presented this part of the world with some major challenges that it must work to overcome. The authors concede that the phenomenon can only partly be attributed to natural causes. In fact, some of the world s most productive and important food crops, such as maize and potatoes, originated in the American tropics. Therefore, a good part of the reason for low yields must be the low level of technology used to produce them the lack of fertilizers, improved seed, and mechanization. Poor agricultural output, the report says, is at least in part caused by poverty rather than being a cause of poverty.
Tropical areas are poorer than temperate areas in part because of a heavier disease burden.
The authors cite vector-borne diseases such as malaria, hookworm and schistosomiasis which cause great suffering and loss of productivity in the tropics, but which have been relatively easy to control in temperate areas because of clearly defined seasons. Although poverty is a cause of poor health, direct geographical influences also have a powerful effect. Controlling for female literacy and income, the authors found that life expectancy is seven years lower in the wet tropics than in the humid temperate zone. Between 1900 and 1995, nearly 640 natural events in Latin America caused severe economic and social hardship. One reason for this disproportion is the region s location on four active tectonic plates, which cause earthquakes and volcanic eruptions.