Who Is the GOP’s Most Electable Candidate?

By Daniel Hopkins

Well, I sure don’t know.  But thanks to the wonders of conditional probability and the data coming from prediction markets like Intrade, we can calculate those markets’ implied answer.  Intrade markets separately give us the probability that a candidate will win his or her party’s nomination and that he or she will win the Presidency in the general election.  From that, figuring out the conditional probability that the candidate will win the November 2012 election having already won the nomination—a proxy for electability—just requires division.

Consider former Alaska Governor Sarah Palin.  As of this morning, one Intrade market gives her a 0.072 probability (or 7.2% chance) of being the GOP nominee, and a separate market gives her a 0.025 probability of being elected President in 2012.  For the moment, grant me the assumption that the bettors are not envisioning her general election victory coming from a third-party candidacy (although if anyone could revive the Bull Moose Party…).  Given that, her implied probability of winning the November election after having won the nomination is .025/.072, or .347.  As compared to the generic Republican nominee’s .378 probability of victory in November, the markets put her at a disadvantage.  The same is true of Michele Bachmann, whose probability of winning in November conditional on being nominated is .339.

Still, prediction markets don’t necessarily handle long-shot candidates well.  So consider instead former Minnesota Governor Tim Pawlenty.  With a .188 probability of winning the GOP nomination and a .071 probability of being elected President, his market-implied probability of winning the White House with the GOP nomination already in hand is 0.377.  His conditional probability of victory in November is almost indistinguishable from the generic GOP nominee’s probability.  It seems that New York Times blogger Nate Silver was right to call him a “league-average politician.”

Now let’s turn to Mitt Romney, another former Governor.  With a .299 chance of winning the GOP nomination and a .123 chance of winning both the nomination and the general election, his implied probability of winning the Presidency given the GOP nomination is 0.411.  But it is former Utah Governor Jon Huntsman that the markets see as the most powerful GOP contender for the fall of 2012.  With a .150 probability of winning the GOP nomination and a .072  probability of winning the Presidency, the Intrade markets imply that Huntsman would have a 0.48 probability of taking the Presidency from the Republican National Convention’s stage in Tampa, Florida.  In other words, to bettors, the GOP candidate (and the events correlated with each candidate’s fortunes) matters markedly.  Conditional on his winning the nomination, they would give Huntsman almost even odds of becoming President in 2012.

[Cross-posted at the Monkey Cage]

Daniel Hopkins is assistant professor of government at Georgetown University.