Jared Diamond (Guns, Germs, and Steel) reviews Why Nations Fail: The Origins of Power, Prosperity, and Poverty, by Daron Acemoglu and James A. Robinson, and brings his own knowledge of geography to answer the question of what makes countries rich or poor?
Two major factors contribute to the poverty of tropical countries compared to temperate countries: diseases and agricultural productivity. The tropics are notoriously unhealthy. Tropical diseases differ on average from temperate diseases, in several respects. First, there are far more parasitic diseases (such as elephantiasis and schistosomiasis) in tropical areas, because cold temperate winters kill parasite stages outside our bodies, but tropical parasites can thrive outside our bodies all year long. Second, disease vectors, such as mosquitoes and ticks, are far more diverse in tropical than in temperate areas.
Finally, biological characteristics of the responsible microbes have made it easier to develop vaccines against major infectious diseases of temperate areas than against tropical diseases; we still aren’t close to a vaccine against malaria, despite billions of dollars invested. Hence tropical diseases impose a huge burden on economies of tropical countries. At any given moment, much of the population is sick and unable to work efficiently. Many women in tropical areas can’t join the workforce because they are constantly nursing and caring for babies conceived as insurance against the expected deaths of some of their older children from malaria.
As for agricultural productivity, it averages lower in tropical than in temperate areas, again for several reasons. First, temperate plants store more energy in parts edible to us humans (such as seeds and tubers) than do tropical plants. Second, diseases borne by insects and other pests reduce crop yields more in the tropics than in the temperate zones, because the pests are more diverse and survive better year-round in tropical than in temperate areas. Third, glaciers repeatedly advanced and retreated over temperate areas, creating young nutrient-rich soils. Tropical lowland areas haven’t been glaciated and hence tend to have older soils, leached of their nutrients by rain for thousands of years. (Young fertile volcanic and alluvial soils are exceptions.) Fourth, the higher average rainfall of tropical than of temperate areas results in more nutrients being leached out of the soil by rain.
Finally, higher tropical temperatures cause dead leaves and other organic matter falling to the ground to be broken down quickly by microbes and other organisms, releasing their nutrients to be leached away. Hence in temperate areas soil fertility is on average higher, crop losses to pests lower, and agricultural productivity higher than in tropical areas. That’s why Argentina in South America’s south temperate zone, despite its conspicuous lack (for most of its history) of the good institutions praised by economists, is the leading food exporter in Latin America, and one of the leading ones in the world.
Thus, geographical latitude acting independently of institutions is an important geographic factor affecting power, prosperity, and poverty. The other important geographic factor is whether an area is accessible to ocean-going ships because it lies either on the sea coast or on a navigable river. It costs roughly seven times more to ship a ton of cargo by land than by sea. That puts landlocked countries at an economic disadvantage, and helps explain why landlocked Bolivia and semilandlocked Paraguay are the poorest countries of South America. It also helps explain why Africa, with no river navigable to the sea for hundreds of miles except the Nile, and with fifteen landlocked nations, is the poorest continent. Eleven of those fifteen landlocked African nations have average incomes of $600 or less; only two countries outside Africa (Afghanistan and Nepal, both also landlocked) are as poor.
The remaining major factor underlying wealth and poverty is the state of the natural environment. All human populations depend to varying degrees on renewable natural resources — especially on forests, water, soils, and seafood. It’s tricky to manage such resources sustainably. Countries that excessively deplete their resources — whether inadvertently or intentionally — tend to impoverish themselves, although the difficulty of estimating accurately the costs of resource destruction causes economists to ignore it. It helps explain why notoriously deforested countries — such as Haiti, Rwanda, Burundi, Madagascar, and Nepal — tend to be notoriously poor and politically unstable.
This would explain why Zimbabwe is so much poorer than Rhodesia. More seriously, Diamond contends that societies with a long history of agriculture also have a long history of government and have thus developed better institutions for economic growth.