Ruggedness: The Blessing of Bad Geography in Africa
研究地形崎岖对非洲收入的直接负面影响和通过奴隶贸易产生的间接正面影响，发现后者占主导，为理解地理与历史交互作用提供证据。
Abstract: There is controversy about whether geography matters mainly because of its contemporaneous impact on economic outcomes or because of its interaction with historical events. Looking at terrain ruggedness, we are able to estimate the importance of these two channels. Because rugged terrain hinders trade and most productive activities, it has a negative direct effect on income. However, in Africa rugged terrain afforded protection to those being raided during the slave trades. Since the slave trades retarded subsequent economic development, in Africa ruggedness also has had a historical indirect positive effect on income. Studying all countries worldwide, we find that both effects are significant statistically and that for Africa the indirect positive effect dominates the direct negative effect. Looking within Africa, we provide evidence that the indirect effect operates through the slave trades. We also show that the slave trades, by encouraging population concentrations in rugged areas, have also amplified the negative direct impact of