The model predicts that during crises, entrepreneurs and civil servants alike are more averse to risk taking and believe they’ll gain more from government wealth distribution. Therefore they’ll be relatively more likely to vote Democratic. Pastor and Veronesi note that transitions to high-tax, left-leaning parties do tend to occur during times of economic crisis.
Using additional assumptions, Pastor and Veronesi’s model also predicts faster economic growth under Democratic presidents. That prediction is also supported in the data. From 1930 to 2015, US real GDP growth under Democratic presidents averaged 5 percent a year, whereas under Republican presidents that was closer to 2 percent. Political cycles thus arise naturally: when growth is low, voters’ risk aversion rises, leading to Democratic victory—after which growth rises, leading to Republican victory, and so on.
Can Pastor and Veronesi’s model explain the postelection run-up? According to the researchers, the market anticipated lower tax rates, which are positive for investors. But before you buy into the Trump rally, keep in mind that history has not been kind to stocks under Republican presidencies.