"In other words, if the average nondemocracy in their sample had transitioned to a democracy its GDP per capita would have increased from $2074 to $2489 in 25 years (i.e. this is the causal effect of democracy, ignoring other factors changing over time). Twenty percent is better than nothing and better than dictatorship but it’s weak tea. GDP per capita in the United States is about 20% higher than in Sweden, Denmark or Germany and 40% higher than in France but I don’t see a big demand in those countries to adopt US practices. Indeed, quite the opposite! If we want countries to adopt democracy, twenty percent higher GDP in 25 years is not a big carrot."