Who's Really Out in Front?

Last month, Supercrunchers author Ian Ayres was guest-posting over at the Freakonomics blog about how likely it might be that a given political candidate is truly leading in the polls. To bolster his argument, he linked to a spreadsheet that, in our view, wasn't the easiest thing in the world to figure out how to use.

That sort of thing is the kind of thing that really gets us going, because each posted spreadsheet on the web is an opportunity to convert it into something truly useful and much easier to use!

So, that's what we did! We've taken Ian's spreadsheet, cut out all the noise distracting commentary and boiled it down to its very essence: a tool you can use to find the likelihood that a given political candidate is really ahead given the results of a particular poll! Just enter the indicated data below and we'll find out what the odds are that a given candidate is truly the front-runner (as always, the best source for the latest polling data is RealClearPolitics):

Polling Data
Input Data	Values
How many people were polled?
What percentage of those polled favor the candidate who appears to be leading?
What percentage of those polled favor the other main candidate in the race?

Who's Really Out in Front?
Calculated Results	Values
Probability that the Candidate Who Appears to Be Leading, Actually Is Leading

Of course, this probability depends upon the polling sample accurately reflecting the actual voting population. As we've seen as a recurring issue with a number of major polls, including this one that perhaps burned Ian Ayres in his original post on the topic, that isn't necessarily the case!