Consider the data compiled by Ned Davis Research, an institutional research firm. In a communication to his clients Thursday morning, Davis reported that the Dow Jones Industrial Average produced an annualized return of 7.21% during Democratic presidents, in contrast to an average of 3.6% during Republican presidents -- or almost precisely half as much, in other words.
Davis hastened to add that he is a political independent, and I should add that during my lifetime I have voted more often for Libertarian presidential candidates than for candidates of either of the major parties. So please don't accuse Davis of biasing his results, or my choosing to write a column on his research, for partisan political reasons.
To be sure, inflation is also higher on average during Democratic presidencies, so on an inflation-adjusted basis there is a smaller difference between the stock market's average returns during presidencies of the two parties. But the Democratic Party still comes out ahead: 2.5% annualized during Democratic presidencies, versus 1.7% during Republican presidencies.
When I mentioned Davis' results to several people on Thursday, the not-infrequent reaction was anger. This baffles me.