I see Matt Yglesias has a post about whether the economy does better under republican or democratic presidents. Here's the graph he should have included:
I started at Eisenhower in 1953 because the data series itself starts abruptly in the middle of Truman's term. More over, as inaguration starts a thrid of the way into first quarter, I have adopted the convention of counting first quarters under the previous president--this is certainly the most reasonable option, since it takes time for presidents to start enacting their own policies. Also, I used Real GDP instead of Real GDP per Capita because the latter preferred series only starts in 1960. This substitution is valid if (as I suspect is true) population growth is uncorrelated with presidential parties. What the figure shows is that every democrat has outperformed every republican with two exceptions:
Reagan actually managed to do a little better than Carter, and
Obama, dealing with the recovery from the worst recession by far in this series, has done worse than everyone.
It is easy to make excuses here. For example, republicans will want to blame Obama for the slow recovery, while Democrats will want to excuse Obama on the basis that Bush II caused the recession in the first place. Similarly, republicans will want to excuse Nixon and Ford, who had large oil shocks to deal with, while Democrat's certainly have plenty of policy grounds to criticize (price controls? really Nixon? and how about Ford's comically dim-witted "Whip Inflation Now" strategy?). The sample size really isn't large enough to rule any of these hypotheses out.
But, just remember that looking at this data and claiming that Republicans are actually better for the economy is a pretty extraordinary claim that requires extraordinary evidence. There were 6 republican presidents and 5 democrats. 5 out 6 republicans beat only 1 out of 5 democrats. And that 6th republican hardly did any better, beating only 2 out of 5 democrats.
