Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I even say who wrote them. If you have more recent summaries to add to this collection, send them my way I guess. Sorry for the ads; they cover the costs of keeping this online.
Balz, John. 2010. Ready to Lead on Day One: Predicting Presidential Greatness from Political Experience. PS, Political Science and Politics 43 (July): 487-492.
We all remember Hillary Clinton's ad--"It's 3:00am and your children are asleep." She wanted voters to believe that her long political experience made her "ready to lead on day one," unlike that untested other guy, Barack Obama. More generally, she wanted us to believe that more experienced presidents are better presidents.
Well, that's a testable question. John Balz tests it in the current issue of PS. He used seven surveys of presidential "greatness," flawed as those surveys may be, and tried to predict each president's "greatness" ranking based on his previous political experience.
Turns out that you can't predict presidential greatness from political experience, at least not very well. Balz reports some weak effects: Former mayors, Congressman, soldiers, and private sector folks have slightly lower ranks. Former generals, state judges, federal administrators, and governors have slightly higher ranks.
But by "slightly," I mean slightly. The effect for governors, though in a favorable direction, rounds off to "0.0" in the table. Same for the estimate for diplomats and state legislators.
This is a fun article. That's why it's in PS and not one of the big three journals. PS is the place for fun articles. There are, of course, some problems here that surely undermine Balz's models, though.
First, there is the obvious problem of sample size. Balz has only 43 former presidents to work with. He's matching them up with 12 different measures of experience. That there is a problem.
Second, it's not clear to me that we would expect the effect of experience to be constant from 1788 through 2008. This isn't an empirical complaint, it's a conceptual one. At the state level, legislative professionalism was a foreign concept until Jesse Unruh became Speaker of the California House in the 1960s. Congressional professionalization came earlier, of course. But presidential "professionalism" was also a late arrival. During Jackson's and Lincoln's day, we saw the presidency make a minor shift away from a mere "chief clerk" toward a genuine chief executive, but that was only a partial transformation. Really, it wasn't until the late 1890s or so--and especially during the Teddy Roosevelt, Woodrow Wilson, and FDR years--that the presidency began to become a dominant national institution. Moreover, it wasn't until the same period that the national government became truly dominant.
If the locus of power was in the states until the very late 1800s, and if government at many levels remained unprofessionalized well into the 1900s, then can we really assume that the effects of experience in 2008 are the same as in 1788?
Again, Balz writes an entertaining paper, but I'm not sure he's really settled the question.
Research on similar subjects