Mitt Romney holds a commanding lead in Florida's primary, with a 98.6 percent likelihood of victory, according to the political prediction markets. Newt Gingrich is 99.9 percent likely to place (i.e., first or second place--almost certainly the latter). Rick Santorum is 85 percent likely to take the bronze from Ron Paul, who holds the remaining 15 percent for third.
It was not all smooth for Romney following Gingrich's domination in South Carolina. There was brief window of time when Gingrich was slightly more likely than Romney to win Florida. This window corresponds to when several polls showed Gingrich with a commanding lead in Florida for about 2 days, but our skepticism in Gingrich holding onto his lead was justified when the same polls quickly reversed themselves.
Gingrich is still leading the Republican national polls; RealClearPolitics' aggregated poll trend has him leading by 2.5 percentage points over Romney. Romney has just 27.8 percentage points compared to Gingrich's 30.3 and Santorum's 16.5. (If we consider Gingrich and Santorum to be the last of the Romney alternatives still standing, we can say the anti-Romney vote is at nearly 50 percent.) Ron Paul, with his ardent and loyal supporters, is at a very steady 12.5 percent. Yet, our models have Gingrich at just 6.6 percent likelihood of winning the nomination to Romney's 87.0 percent.
Prediction markets represent the combined analysis of many people, but the extreme confidence in Romney is probably founded in the same political wisdom that has many people suggesting the contest is winding down. Romney has a much more extensive national organization than his two closest competitors--only Paul has the people on the ground to fight Romney in all the primary contests. The former Massachusetts governor also has a huge monetary advantage that Romney put into full effect in Florida.
David Rothschild is an economist at Yahoo! Research. He has a Ph.D. in applied economics from the Wharton School of Business at the University of Pennsylvania. His dissertation is in creating aggregated forecasts from individual-level information. Follow him on Twitter @DavMicRot and email him at firstname.lastname@example.org.