Rule of Law
Economists have repeatedly found that the better the rule of law, the richer the nation. (The chart below, by Daniel Kaufmann, shows the results of three studies). Every rich country with the arguable exceptions of Italy and Greece scores well on rule-of-law measures; most poor countries do not.
Some new research finds only a weak link between the rule of law and recent economic growth. The connection with wealth is well established but that is different: it has been forged over decades, even centuries.
As usual, correlation does not imply causation. Perhaps growth helps the rule of law, not vice versa. Perhaps countries can afford the luxury of the rule of law only after they have grown rich.
“Order in the Jungle,” The Economist