Larry Bartels contemplates the finding and others like it:

We often think of election outcomes as collective verdicts on the state of the nation under the incumbent president. As political scientist Morris Fiorina put it long ago, "In order to ascertain whether the incumbents have performed poorly or well, citizens need only calculate the changes in their own welfare." Are we better off now than we were four years ago? What happens, then, if citizens are not really up to calculating "changes in their own welfare"—if our judgments about even the most salient and straightforward aspects of our collective well-being are based more on partisan biases and media buzz than on reality?