Thursday, October 30, 2008

Five Thirty Eight

Continuing this political thread, I am have recently discovered the website Five Thirty Eight. Its name derives from the amount of electors in the electoral college, and its purpose is to accurately predict the election.

"How is this site different from other compilations of polls like Real Clear Politics," you ask? The website addresses this:
There are several principal ways that the FiveThityEight methodology differs from other poll compilations: Firstly, we assign each poll a weighting based on that pollster's historical track record, the poll's sample size, and the recentness of the poll. More reliable polls are weighted more heavily in our averages. Secondly, we include a regression estimate based on the demographics in each state among our 'polls', which helps to account for outlier polls and to keep the polling in its proper context. Thirdly, we use an inferential process to compute a rolling trendline that allows us to adjust results in states that have not been polled recently and make them ‘current’. Fourthly, we simulate the election 10,000 times for each site update in order to provide a probabilistic assessment of electoral outcomes based on a historical analysis of polling data since 1952. The simulation further accounts for the fact that similar states are likely to move together, e.g. future polling movement in states like Michigan and Ohio, or North and South Carolina, is likely to be in the same direction.

Basically, this is the most sophisticated election projection that I've seen. Right now Obama has a 95.7% chance to win the election, and the most likely scenario has him with 52% of the popular vote and 344.1 electoral votes (with 270 needed to win the presidency). The website also predicts that Democrats will come away with 57 seats in the Senate, though there is a 33% chance that they will reach the filibuster-proof 60.

I am interested to find out how accurate these projections are come Tuesday.

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