The geography hypothesis is simply too broad and tries to explain too much. If geography were the sole or primary factor responsible for inequality, then North and South Korea would be equally rich, and Mexico and Peru would not have gone from rich to poor over time. While inequality is a stubborn global pattern, it has shifted in important ways over history. But geography hasn’t changed significantly—at least between the formation of the first human societies and the modern era of climate change. Therefore, inequality must depend on a factor
besides geography—a factor that changed sometime during the period of European colonialism. Notably, Acemoglu and Robinson aren’t saying that geography
never affects different nations’ fate, but rather that it isn’t the main cause of inequality.