A statistical assessment of Buchanan's vote in Palm Beach County

Abstract

This article presents a statistical analysis of the results of the 2000 U.S. presidential election in the 67 counties of Florida, with particular attention to the result in Palm Beach county, where the Reform party candidate Pat Buchanan recorded an unexpectedly large 3,407 votes. It was alleged that the "butterfly ballot'' had misled many voters into voting for Buchanan when they in fact intended to vote for Al Gore. We use multiple regression techniques, using votes for the other candidates and demographic variables as covariates, to obtain point and interval predictions for Buchanan's vote in Palm Beach based on the data in the other 66 counties of Florida. A typical result shows a point prediction of 371 and a 95% prediction interval of 219--534. Much of the discussion is concerned with technical aspects of applying multiple regression to this kind of data set, focussing on issues such as heteroskedasticity, overdispersion, data transformations and diagnostics. All the analyses point to Buchanan's actual vote as a clear and massive outlier.