Political scientists give Obama 80% chance of victory Nick Juliano and Muriel Kane

Published: Thursday October 16, 2008





Print This Email This Models predicted Bush win in '04 Even before the current economic turmoil steered more voters towards Barack Obama, political scientists were predicting the Democratic candidate would win the presidency.



Election forecasts completed this year give Obama an 80 percent chance of victory. Just one of nine forecast models being published this month predicts John McCain will win, and that model relies heavily on poll results inflated by the substantial bounce that running mate Sarah Palin briefly provided the Republican ticket.



Between January and September, political scientists began comparing statistics including economic data, the candidate's poll numbers, President Bush's approval ratings and other figures to create statistical models aimed at forecasting the 2008 election results. Nine models are being published this month in the journal of the American Political Science Association.



Of the nine models, six predict an Obama victory, with three of those predicting a landslide. Another two are too close to call. The models also weigh the probability of their predicted outcomes; the median result predicts an 80 percent chance Obama will win.



The same journal published similar models before the 2004 election. Six of seven forecasts predicted President Bush would win (the seventh predicted Bush would receive 49.9 percent of the vote).



Statistician Nate Silver, who blogs at FiveThirtyEight.com, predicts a 95 percent chance Obama will win, and the political exchange market Intrade puts Obama's chances above 85 percent.



The earliest of the predictions to be published in the political science journal, from January 2008, was based on the degree of support for each of the candidates in early primaries, and showed a too-close-to-call result, with of 50.1% of the popular vote goting to Obama and 49.9% to McCain.



Five predictions from last summer basically treated the election as a referendum on both President Bush and the state of the economy. Four of those showed Obama winning comfortably with anything between 52.2% and 58.2% of the popular vote.



The fifth came up with a raw figure of 56.57% for Obama but then lowered it to a virtual tie to reflect the impact of race on voters' preferences.



Two other predictions from July and August, which used more complex statistical models based on federal and state factors, also predicted an Obama victory with 52% or 53% of the vote.



The only prediction of a McCain victory came in September and combined second-quarter economic figures with the Gallup Poll numbers from Labor Day -- which was the scheduled first day of the Republican National Convention and just three days after McCain's attention-getting announcement of Sarah Palin as his running-mate. It showed McCain gaining 52.7% of the popular vote.







