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Delphi Surveys

Delphi survey #3
Delphi survey #2
Delphi survey #1


29 October 2004

It's Bush by a Nose in a Photo-Finish Election in Delphi Survey #3

Scott Armstrong, The Wharton School
Randall Jones, University of Central Oklahoma
Alfred Cuzán, University of West Florida
(with the assistance of Cati Verdi)

In the third and last Delphi Survey on this year's presidential election completed this week, a panel of 17 American politics experts (see list, below) predicts a hair-splitting, one-percent margin of victory for President Bush in the two-party vote for president (that is, omitting third-party candidates). The experts were 95% certain that Bush will receive at least 48% and not more than 53% of the two-party vote. The lower bound of the forecast being below 50 percent, our panel believes that this election could go either way. If our panel's point prediction proves accurate, it would be the closest margin of victory for a sitting president since Cleveland beat Harrison in 1888, only to lose in the Electoral College.

As far as we know, this is the first time that the Delphi method has been used for presidential election forecasting. As in our previous two surveys, each of the experts first made a prediction of the most likely forecast of the vote, along with “best case” and “worst case” outcomes for Bush, offering reasons for each. Next, the experts were shown the individual predictions made by their peers in the survey and the reasons offered for them, along with the median and other statistics for the group. The experts were then asked to revise their predictions in light of this information.

Clearly a survey of 17 experts is less expensive than an intentions survey of 1,000 people. It also has an advantage over polls because experts not only have much more information, they also know about bell-weather states, other historical trends and patterns, and theories that account for how past elections turned out. Thus, our expectation is that our panel's forecast will be closer to the actual outcome than the average of the polls.

Participants in Survey #3.

  1. Randall Adkins – Associate Professor of Political Science, University of Nebraska at Omaha

  2. Michael Barone - Senior Writer, U. S. News and World Report

  3. Karlyn Bowman - Resident Fellow, American Enterprise Institute

  4. George Edwards – Distinguished Professor of Political Science and Jordan Chair in Presidential Studies, Bush School of Government and Public Service, Texas A & M University.

  5. Ada Finifter - Professor of Political Science, Michigan State University

  6. Chris Garcia – Professor of Political Science and former President of the University, University of New Mexico

  7. Karen Hult – Professor of Political Science, Virginia Polytechnic Institute and State University (Virginia Tech)

  8. Gary Jacobson – Professor of Political Science, University of California, San Diego

  9. Charles O. Jones – Nonresident Senior Fellow, The Brookings Institution and Hawkins Professor of Political Science Emeritus, University of Wisconsin

  10. Kenneth Mayer – Professor of Political Science, University of Wisconsin

  11. Leon Panetta – Director of the Panetta Institute of Public Policy, California State University, Monterey Bay

  12. Thomas Patterson – Bradlee Professor of Government and the Press, Kennedy School of Government, Harvard University

  13. Larry Sabato – Gooch Professor of Politics and Director of the Center for Politics, University of Virginia

  14. Harold Stanley – Geurin-Pettus Distinguished Chair in American Politics and Political Economy, Southern Methodist University

  15. Charles Walcott – Professor of Political Science, Virginia Polytechnic Institute and State University (Virginia Tech)

  16. Martin Wattenberg – Professor of Political Science, University of California, Irvine

  17. Herbert Weisberg – Professor of Political Science, Ohio State University

30 September 2004

Experts Give the Edge to Bush in Delphi Survey #2

Scott Armstrong, The Wharton School
Randall Jones, University of Central Oklahoma
Alfred Cuzán, University of West Florida
(with the assistance of Cati Verdi)

In the second Delphi Survey completed this week, a panel of 16 American politics experts predict a narrow Bush win with 51 percent of the two-party vote (that is, omitting minor party candidates). The experts were 95% certain that Bush will receive at least 48% and not more than 54%. This represents a shift from the previous survey, when Kerry was forecast to win by about the same margin.

As far as we know, this is the first time that the process, called a Delphi Survey, has been used for presidential election forecasting. Clearly a survey of 16 experts is less expensive than an intentions survey of 1,000 people. It also has an advantage over polls because experts are familiar with much more information, they have knowledge about how future events (e.g., debates) might affect preferences, and there is no need for a probability sample.

As in our first survey, each of the experts first made a prediction of the most likely forecast of the vote, along with forecasts of a “best case” and “worst case” outcomes for Bush, offering reasons for each prediction. Next, the experts were shown the individual predictions made by their peers in the survey and the reasons offered for them, along with the average and other statistics for the group. The experts were then asked to revise their predictions in light of this information.

We plan to administer one more survey in October.

Participants in Survey #2.

  1. Randall Adkins – Associate Professor of Political Science, University of Nebraska at Omaha
  2. Michael Barone - Senior Writer, U. S. News and World Report
  3. Karlyn Bowman - Resident Fellow, American Enterprise Institute
  4. George Edwards – Distinguished Professor of Political Science and Jordan Chair in Presidential Studies, Bush School of Government and Public Service, Texas A & M University.
  5. Ada Finifter - Professor of Political Science, Michigan State University
  6. Chris Garcia – Professor of Political Science and former President of the University, University of New Mexico
  7. Karen Hult – Professor of Political Science, Virginia Polytechnic Institute and State University (Virginia Tech)
  8. Gary Jacobson – Professor of Political Science, University of California, San Diego
  9. Charles O. Jones – Nonresident Senior Fellow, The Brookings Institution and Hawkins Professor of Political Science Emeritus, University of Wisconsin
  10. Leon Panetta – Director of the Panetta Institute of Public Policy, California State University, Monterey Bay
  11. Thomas Patterson – Bradlee Professor of Government and the Press, Kennedy School of Government, Harvard University
  12. Larry Sabato – Gooch Professor of Politics and Director of the Center for Politics, University of Virginia
  13. Harold Stanley – Geurin-Pettus Distinguished Chair in American Politics and Political Economy, Southern Methodist University
  14. Charles Walcott – Professor of Political Science, Virginia Polytechnic Institute and State University (Virginia Tech)
  15. Martin Wattenberg – Professor of Political Science, University of California, Irvine
  16. Herbert Weisberg – Professor of Political Science, Ohio State University

2 August 2004

Experts Predict a Very Close Election; Slight Advantage to Kerry

Scott Armstrong, The Wharton School
Randall Jones, University of Central Oklahoma
Alfred Cuzán, University of West Florida

To forecast the outcome of the presidential election, in late July we conducted a survey of political scientists and other close observers of the American electoral process.[1] This group of fifteen experts (see list appended at the end of this note) predicted that Democratic presidential nominee John Kerry will win a bare majority of the major-party vote in a close election. The median prediction – that is, the estimate at the midpoint for the group – was that Kerry would get 50.5% of the two-party vote. The experts also were 95% certain that Kerry’s vote would be at least 48% and not more than 54%, again using the median scores. (The slight asymmetry in the confidence interval around the point prediction reflects one or more such asymmetries in the individual predictions themselves.) These findings suggest that, in fact, the election is too close to call.

In contrast to traditional polls, in which individual members of the public are asked how they will vote, in surveys such as this one the experts are asked to predict how the public as a whole will vote. Using the survey procedure known as Delphi, every participant first makes an anonymous prediction of the most likely forecast of the vote, along with forecasts of a “best case” and “worst case” outcome for one of the candidates (in this case, the incumbent, President Bush), offering reasons for each prediction. Next, panel members are shown the individual predictions made in the first round and the reasons given for them, as well as forecast averages and other descriptive statistics for the group. Panelists are then asked to revise their estimates in light of this information.

This is believed to be the first time that Delphi has been used to forecast a presidential election. The technique has an advantage over public opinion polls in that experts can have knowledge about future events and how they might affect voter preferences. In addition, the experts are familiar with a wide range of academic studies and other information that can provide insights into the election.

We plan to administer at least two more surveys of the panel before the November election.

Participants in This Delphi Survey

  1. Randall Adkins – Associate Professor of Political Science, University of Nebraska at Omaha
  1. George Edwards – Distinguished Professor of Political Science and Jordan Chair in Presidential Studies, Bush School of Government and Public Service, Texas A & M University.
  1. Ada Finifter – Professor of Political Science, Michigan State University
  1. Chris Garcia – Professor of Political Science and former President of the University, University of New Mexico
  1. Karen Hult – Professor of Political Science, Virginia Polytechnic Institute and State University (Virginia Tech)
  1. Gary Jacobson – Professor of Political Science, University of California, San Diego
  1. Charles O. Jones – Nonresident Senior Fellow, The Brookings Institution and Hawkins Professor of Political Science Emeritus, University of Wisconsin
  1. Kenneth Mayer – Professor of Political Science, University of Wisconsin
  1. Leon Panetta – Director of the Panetta Institute of Public Policy, California State University, Monterey Bay
  1. Thomas Patterson – Bradlee Professor of Government and the Press, Kennedy School of Government, Harvard University
  1. Larry Sabato – Gooch Professor of Politics and Director of the Center for Politics, University of Virginia
  1. Harold Stanley – Geurin-Pettus Distinguished Chair in American Politics and Political Economy, Southern Methodist University
  1. Charles Walcott – Professor of Political Science, Virginia Polytechnic Institute and State University (Virginia Tech)
  1. Martin Wattenberg – Professor of Political Science, University of California, Irvine
  1. Herbert Weisberg – Professor of Political Science, Ohio State University

Further Information About Delphi

The following sources, available on-line, provide details about the Delphi technique:


[1] We were ably assisted in this project by Cati Verdi, whose help we gratefully acknowledge.

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