The authors explain how, for the third time since its appearance in 2004, the PollyVote (www.polyvote.com) has demonstrated the value of combining forecasts to predict the two-party popular vote in U.S. presidential elections. Copyright International Institute of Forecasters, 2013

Using the index method, we developed the PollyBio model to predict election outcomes. The model, based on 49 cues about candidates’ biographies, was used to predict the outcome of the 28 U.S. presidential elections from 1900 to 2008. In using a simple heuristic, it correctly predicted the...

At PoliticalForecasting.com, better known as the Pollyvote, the authors combine forecasts from four sources: election polls, a panel of American political experts, the Iowa Electronic Market, and quantitative models. The day before the election, Polly predicted that the Republican ticket's share...

Ideally, presidential elections should be decided based on how the candidates would handle issues facing the country. If so, knowledge about the voters’ perception of the candidates should help to forecast election outcomes. We make two forecasts of the winner of the popular vote in the U.S....

The Delphi technique is better than traditional group meetings for forecasting and has some advantages over another promising alternative to meetings, prediction markets. In this article, Kesten, Scott, and Andreas observe the increasing popularity of Delphi, describe the benefits of using this...

We conducted laboratory experiments for analyzing the accuracy of three structured approaches (nominal groups, Delphi, and prediction markets) relative to traditional face-to-face meetings (FTF). We recruited 227 participants (11 groups per method) who were required to solve a quantitative...

We conducted laboratory experiments for analyzing the accuracy of three structured approaches (nominal groups, Delphi, and prediction markets) relative to traditional face-to-face meetings (FTF). We recruited 227 participants (11 groups per method) who were required to solve a quantitative...

This paper summarizes the key conditions under which the index method is valuable for forecasting and describes the procedures one should use when developing index models. The paper also addresses the specific concern of selecting inferior candidates when using the bio-index as a nomination...

This study uses 59 biographical variables to create a "bio-index" for forecasting U.S. presidential elections. The bio-index method counts the number of variables for which each candidate rates favorably, and the forecast is that the candidate with the highest score would win the popular vote....

We summarize the literature on the effectiveness of combining forecasts by assessing the conditions under which combining is most valuable. Using data on the six US presidential elections from 1992 to 2012, we report the reductions in error obtained by averaging forecasts within and across four...