Lies, Damn Lies, and Pre–Election Polling

In this paper we ask the question: how well do pre–election polls forecast the actual results of elections in the U.S.? 1 The question is interesting for a number of reasons. First, even polling data suggests about 1/3 of polling respondents do not believe that polls work in " the best interests of the general public. " 2 The situation is such that even many national governments have undertaken to restrict some aspect of pre–election polling. A 1997 international survey of governments, for example, found 30 of 78 surveyed nations had some kind of ban on publication of poll results. Second, there is a strong presumption in the literature on professional forecasting in other contexts (such as interest rate forecasting), which do not rely on sampling per se, that forecasts will be biased. There are a variety of explanations for why forecasts will be biased; one " honest " motivation is that pollsters may avoid reporting results from the unavoidable " atypical " polls. Third, in