Causality and Policy Outcomes: The Case of Presidents and Economic Growth

A headline correlation. This paper will make the rounds for awhile. But something of a side note may eclipse it:

Their bottom line? The residual difference in economic growth observed between Republican and Democrat presidents is a "mystery." What BW13 may have actually rediscovered is that we don't know where economic growth actually comes from. Solving that riddle will require going beyond simple statistics.

Science is hard.