Over at the Upshot.
Read the piece, but the general finding has been widely known by those who plumb the data: on average, the economy, as measured by many macro and financial indicators, does better under D presidents. The paper I review in the piece, by Alan Blinder and Mark Watson, goes further than earlier work in examining why. As you’ll see, the factors they identify look more like luck than “skill,” though who knows? Untangling such things over presidential terms, with so many moving parts, goes well beyond both the data and our statistical techniques.
Extra bonus for OTEers: here’s a point I liked that got cut:
One bit of evidence for this “who knows?” position comes out of B&W’s own work. Even putting aside the question of whether D’s deserve credit, based on the paper’s findings you might think that a forecaster guessing about future GDP growth would generate more accurate predictions by simply adding the president’s party to her equation. Alas, she would not. The D-R gap is a cumulative result that holds over the last six decades but that signal isn’t strong enough in real time to improve your estimates about next year.