Agriculture, climate, and technology: Why are the tropics falling behind?

The tropics, sadly, continues to be a belt of poverty. The countries of the tropics all have low or middling incomes, with a few tiny or natural-resource-rich exceptions, and few of the poorest countries are outside of the tropics. The causes of tropical poverty are surely complex, involving initial endowments (Diamond), history, especially colonization, and geographical isolation (Gallup and Sachs 1999a). Central to the tropical poverty trap, though, is the impact of climate on productivity through the channels of tropical disease ecology and agriculture. This paper investigates the last channel: the causes of lower agricultural productivity in the tropics.