a1 University at Buffalo, SUNY
The October 2008 issue of PS published a symposium of presidential and congressional forecasts made in the summer leading up to the election. This article is an assessment of the accuracy of their models.
On September 8, 2008, the Trial-heat Forecasting Model predicted that in-party candidate Senator John McCain would receive 52.7% of the national two-party popular presidential vote. The forecast of a victory of modest proportions for Senator McCain reflected his having a five-percentage-point lead over Senator Barack Obama in Gallup's early September, post-convention poll (49% to 44%) and the Bureau of Economic Analysis' August report of a 3.3% GDP growth rate in the second quarter of the year, about average for a second quarter election year economy.
James E. Campbell is a professor of political science and department chair at the University at Buffalo, SUNY. His most recent book is The American Campaign, Second Edition: U.S. Presidential Campaigns and the National Vote and he recently co-edited a special issue of the International Journal of Forecasting on presidential election forecasting with Michael Lewis-Beck. He has published four books and numerous journal articles and book chapters. He is a former APSA Congressional Fellow and program director at the National Science Foundation. He currently serves as president of Pi Sigma Alpha.