Why are some societies characterized by enduring democracy, while other societies are either persistently autocratic or experiment with democracy but then quickly fall back into autocracy? I find that there is a systematic, non-linear relationship between rainfall levels, human capital, property...

Scientists will long debate the extent to which our climate is changing as a result of anthropogenic releases of greenhouse gases. But the debate over whether the earth is experiencing climate change-and in particular, global warming, is pretty much over. Much good work is being done to address...