This document discusses index models for forecasting elections. It describes how index models summarize prior knowledge about a domain using variables to predict outcomes. It then presents a bio-index model that uses 59 biographical variables to predict US presidential election winners from 1896-2008 with 93% accuracy. The model is then used to forecast the 2012 election, predicting that only Rick Perry would defeat Obama based on candidates' biographical index scores.
9. Who should be nominated to run in the 2012 U.S. presidential election? Long-term forecasts based on candidates’ biographies Andreas Graefe, Sky Deutschland J. Scott Armstrong, Wharton School, University of Pennsylvania This talk is an extension of : tinyurl.com/bioindex International Symposium on Forecasting Prague, June 27, 2011
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21. Prediction problem Forecast U.S. presidential election outcome from information about candidates’ biographies
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31. Bio-index vs. 7 regression models (1996-2008) Absolute error of out-of-sample forecasts for the past four elections Bio-index MAE as low as MAE of most accurate model Bio-index forecast calculated long before the forecast of most other model Model Date of forecast 1996 2000 2004 2008 MAE Bio-index January 4.4 2.3 0.4 0.2 1.8 Norpoth January 2.4 4.7 3.5 3.6 3.5 Abramowitz Late July 2.1 2.9 2.5 0.6 2.0 Fair Late July 3.5 0.5 6.3 2.2 3.1 Wlezien and Erikson Late August 0.2 4.9 0.5 1.5 1.8 Lewis-Beck and Tien Late August 0.1 5.1 1.3* 3.6 2.5 Holbrook Late August 2.5 10.0 3.3 2.0 4.4 Campbell Early September 3.4 2.5 2.6 6.4* 3.7 * Predicted wrong election winner
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35. * Announced to run; **RCP and Intrade forecasts as of June 25, 2011 Candidate Chance to win GOP nomination Chance to win election (Intrade**) Index score difference Index model forecast RCP polls** Intrade** 5.3 17.1 6.6 +1 50.3 David Petraeus 0 0.1 0 0 49.5 Newt Gingrich* 7.1 1.3 1.0 -2 47.9 Donald Trump 0 0.2 0.6 -2 47.9 Michele Bachmann* 6.3 9 2.8 -2 47.7 Rudy Giuliani 11.0 1.8 0 -3 47.0 Mitt Romney* 24.4 35.6 16.5 -4 46.3 Tim Pawlenty* 4.9 9.8 4.0 -4 46.1 Rick Santorum* 3.7 0.6 0.2 -4 46.1 Jon Huntsman* 1.3 9.6 5.4 -5 45.3 Sarah Palin 16.0 5.1 3.2 -5 44.6 Ron Paul* 6.9 2.4 1.7 -6 44.4 Mike Huckabee 0 0.2 0.2 -6 43.8 Herman Cain* 9.3 2.0 1.3 -7 43.0
36. * Announced to run; **RCP and Intrade forecasts as of June 25, 2011 Candidate Chance to win GOP nomination Chance to win election (Intrade**) Index score difference Index model forecast RCP polls** Intrade** Rick Perry 5.3 17.1 6.6 +1 50.3 David Petraeus 0 0.1 0 0 49.5 Newt Gingrich* 7.1 1.3 1.0 -2 47.9 Donald Trump 0 0.2 0.6 -2 47.9 Michele Bachmann* 6.3 9 2.8 -2 47.7 Rudy Giuliani 11.0 1.8 0 -3 47.0 Mitt Romney* 24.4 35.6 16.5 -4 46.3 Tim Pawlenty* 4.9 9.8 4.0 -4 46.1 Rick Santorum* 3.7 0.6 0.2 -4 46.1 Jon Huntsman* 1.3 9.6 5.4 -5 45.3 Sarah Palin 16.0 5.1 3.2 -5 44.6 Ron Paul* 6.9 2.4 1.7 -6 44.4 Mike Huckabee 0 0.2 0.2 -6 43.8 Herman Cain* 9.3 2.0 1.3 -7 43.0
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Notas do Editor
Fair‘s model correctly predicted the winners in the 1980, 1984, and 1988 elections but failed to predict the easy re-election of Bush in 1992.
Keys To The White House 1: Party Mandate 2: Party Contest 3: Incumbency 4: Third Party 5: Short-term Economy 6: Long-term Economy 7: Policy Change 8: Social Unrest 9: Scandal 10: Foreign or Military Failure 11: Foreign or Military Success 12: Incumbent Charisma/Hero 13: Challenger Charisma/Hero
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