Mitt Romney and Rick Santorum slugged it out tonight in Arizona, but the importance was all about Michigan. Santorum, as the frontrunner in the polls, was on the defensive for most of the night. Romney, as the actual frontrunner, was playing it safe. The

As though New Hampshire wasn’t already overprivileged enough in the broken primary system, the state may be the one to tip the scales in the general election to either party. According to my new elections model, which orders the states from most

We’ll dip into what the model says in a moment, but first a note about models in general: there are a lot of them, from complex equations generated by nerdy academics (like the work by Patrick Hummel and I seen here) to

Rick Santorum has slipped ahead of the Mitt Romney in the polls, marking an ignominious milestone in the Republican nomination: Since last summer, when Romney was at the top of the early polls, the lead has switched nine times. In order, it’s

Regardless of what happens tonight, Romney is still the heavy favorite to win the Republican nomination at 84.5 percent. That numbers assumes that he will likely lose in Minnesota and has a non-negligible likelihood of finishing third or even fourth in Minnesota. The

This is the table to follow this evening as the Minnesota Presidential Caucus unfolds:

Here’s one way to think about it: There are two sources of uncertainty when we model predictions for political elections and sports: incomplete information and true randomness. First, there is information we do not know or cannot model. In politics we do

Last Tuesday, the Susan G. Komen Foundation announced it would no longer fund clinical breast exams and mammograms through Planned Parenthood. The $680,000 per year that was going to Planned Parenthood helped provide exams for 170,000 mainly low-income and minority women. The

The first thing that most people associate with Nevada is Vegas. About 70 percent of the population lives in Clark County, home to Las Vegas and the surrounding metro area. In 2008, Barack Obama won the county by nearly 20 percentage points. But Nevada&

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

Just after the South Carolina primary, where Newt Gingrich won a dominating victory, the former speaker inched up to an almost 30 percent likelihood of winning the nomination, according to prediction market data. At the time, it was a major foray in Romney territory;

As he prepares for his third State of the Union address–and, he hopes, not his last–Barack Obama’s likelihood of reelection has soared in the last few days to 56.8 percent, the highest it has been since last

Newt Gingrich has won the South Carolina primary, elevating him to a 25 percent chance to win the Republican nomination in online futures markets. This is the first serious assault we’ve seen on Romney’s once iron grip on this particular

So here’s the question: if the most conservative estimates are correct and 10,000 eligible voters are disenfranchised so that 100 non-eligible votes can be stopped, do you think that that is a fair deal for democracy? What if the more mainstream

Just yesterday, the political prediction markets gave Mitt Romney an 85 percent chance of winning Saturday’s primary in South Carolina. With this morning’s news that Rick Perry is dropping out and endorsing Newt Gingrich, Gingrich appears to be consolidating the

With Jon Huntsman’s exit from the Republican primary race there are five main candidates left, and Mitt Romney holds a commanding lead among them with a 89.1 percent chance of gaining the Republican nomination, according to prediction market data. Ron Paul

Mitt Romney went into Iowa as the heavy favorite to win the Republican nomination and he leaves New Hampshire in the same position. Unlike the see-saw like swings in the Democratic nomination battle of 2008 or the steady movement in the Republican nomination battle

Mitt Romney is heavily favored to win both the New Hampshire primary and, eventually, the Republican nomination. Utilizing prediction market data, Romney has a 97.3 percent likelihood to win the New Hampshire primary and an 80.0 percent likelihood to win the nomination.

The continued position of Spreading Santorum and other sites is a reflection of what Internet users want to read about. Chris Wilson, now with us at The Signal, wrote a few months ago in Slate that Spreading Santorum’s prevalence cannot simple be

Where prediction markets really showed their value was in the real-time aggregation of information. They did not favor Romney all night long, but were constantly digesting and aggregating all the recent and relevant dispersed information. Just as voting began, entrance polling showed that Ron

A few hours before the Iowa caucuses begin, Mitt Romney is just over 50 percent likely to win this first-in-the-nation primary contest, according to data from the prediction markets Betfair and Intrade. This is a strong recovery for the candidate, who was trailing both

This week the real action begins in two beloved American sports: politics and football. And analyzing the football playoffs can tell us a lot about how we predict elections. Using prediction market data from Betfair and Intrade, the Green Bay Packers have a 32

The chart shows how these three main predictions have shifted during the course of the year. Obama had a small spike when Osama Bin Laden was captured, but otherwise he’s been on a slow decline for most of the summer and early

Gambling is about demonstrating confidence in potential wins and losses. Romney is making an investment with a huge potential upside and small potential cost. For Gingrich and Perry a poor showing in Iowa followed by a beating in New Hampshire would leave both limping

On Monday, neoconservative leader, George W. Bush foreign policy cheerleader, and early supporter of Sarah Palin, Bill Kristol, made an emotional plea for a new anyone-but-Romney candidate to join the race for the Republican nomination. Yet Gingrich’s woes show that it is