• Forecasting 2012

    by  • June 26, 2012 • 2 Comments

    Welcome to the new site. I’ll start with some background. About a year ago, I started circulating a research paper describing a statistical model for forecasting presidential elections and tracking voter preferences at the state level. The model gives us a way to combine data from past elections with the results of every new state-level poll, as they’re released, in real time. When I tested it out on the pre-election polls from 2008, it quickly and accurately predicted an Obama victory, and clearly outperformed projections based on historical factors alone.

    I’ve set up this site to keep track of what’s happening in 2012. As we get closer to Election Day, more polls will come out, and we’ll have a better sense of who’s likely to win. The trick is that there are some things we’d like to know right now: not only the probable election winner, but also which states are going to be competitive, and how voter preferences are changing over time. This is what my model tells us, for every state, on every day of the campaign. I then aggregate the state results to see who’s ahead in the Electoral College, and calculate each candidate’s probability of victory.

    As new polls become available, estimates on the site will update automatically, usually daily. The top banner will contain the current national forecasts, as well as the trend in past forecasts, so you can see if there are any sudden shifts or changes (there shouldn’t be), or if newer polling data are causing a reassessment of earlier predictions. The forecast tracker page shows the same information for all 50 states. On the forecast detail page, you’ll find the most up-to-date state forecasts, as well as the distribution of potential electoral vote outcomes. The poll tracker page will show smoothed trends in preferences for Obama vs. Romney up to the most recent day. For more on the model itself, there’s a separate page on how it works.

    I’ll also be chiming in here now and then. But check back anyway. Even if I don’t have anything new to say, the site will continue to update to reflect the latest polls.