“The economy invariably ranks among the top issues on the minds of voters in presidential elections. At the moment, it appears to offer President Trump a meaningful tailwind.
But how big is that tailwind? Fortunately, economists have worked hard to develop models for predicting election outcomes, and according to one of the best of these, it should be quite large.
One of the first — and perhaps still the best — of these models was created by Ray Fair, a professor at Yale. He found that the growth rates of gross domestic product and inflation have been the two most important economic predictors — but he also found that incumbency was also an important determinant of presidential election outcomes.
How well has Professor Fair’s model worked?
In short, while not perfect, the Fair model has done remarkably well. In 2008, it predicted that Barack Obama would receive 53.1 percent of the popular vote; his share actually totaled 53.7 percent. In 2012, when Mr. Obama was running for re-election, its final estimate was a vote share of 51.8 percent, just two-tenths of one percent less than what the incumbent president received. (For Mr. Obama in 2012, the power of incumbency helped offset a still-recovering economy.)”