PollyVote

PollyVote is the name of a website and its private prediction model operated by several professors of political science and other academics which, during fall 2008, is providing a daily prediction related to the upcoming 2008 United States Presidential Election. The specific outcome it predicts is the Republicans' share of popular two-party vote. The prediction model employed combines different forecasting methods, which its advocates assert should provide it with better predictive ability than some other prediction approaches.

It is comparable to the Iowa Electronic Markets which, through the information-collecting activities of participants in its betting system, conceivably incorporates all types of information and models incorporated in the PollyVote's system, including the Pollyvote's daily forecast output, which is publicly available.

While the IEM handles new information in complex ways, the PollyVote's method of combination of the several sources of information is simply to take an average of them.cite web|url=http://blogs.wsj.com/numbersguy/the-wisdom-of-political-crowds-425/ |title=The Wisdom of Political Crowds |author=Carl Bialik
date=October 7, 2008 |accessdate=2008-10-08 |work="The Numbers Guy" blog |publisher=Wall Street Journal blogs]

History

The PollyVote was created in 2004 to demonstrate the power of combining forecasts for U.S. Presidential Elections [Campbell, James E. & Lewis-Beck, Michael S. (2008), [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V92-4S4J6G5-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=f954c119afb661094159646ec1b34bfe US presidential election forecasting: An introduction] , International Journal of Forecasting, 24(2), 189-192] . It forecasted a victory for President Bush over the 8 months that it was making forecasts, and it predicted on the morning of the election that George W. Bush would receive 51.5% of the popular vote, an error of 0.3 percentage points.

PollyVote also predicted the outcome of the 2006 U.S. House of Representatives Elections, forecasting that the Republicans would lose 23 seats, and thus, their majority in the House. The Republicans lost 30 seats and the House majority in those elections.

PollyVote is currently forecasting the outcome of the 2008 US Presidential Election with daily updates, for which it has been referenced by MarketWatch from the Wall Street Journal [ MarketWatch: [http://www.marketwatch.com/news/story/obama-shoo-forecasting-models-say/story.aspx?guid={1662DD33-EA15-4228-A2B5-222A7A95E1B9} "Obama a shoo-in, forecasting models say"] , Rex Nutting, Wall Street Journal: Market Watch; July 3, 2008. ] as well as the Sueddeutsche Zeitung [ Sueddeutsche Zeitung: [http://www.sueddeutsche.de/wissen/199/305169/text/ "Zauberformeln für den Wählerwillen"] , August 6, 2008.] , Germany's largest broadsheet daily.

Pollyvote's components

PollyVote currently consists of four components: opinion polls, a prediction market, expert judgments and quantitative models. PollyVote combines forecasts from different components in an attempt to reduce forecast error. [ [http://marketing.wharton.upenn.edu/ideas/pdf/Armstrong/CombiningForecasts.pdf Principles of Forecasting: A Handbook for Researchers and Practitioners] , J. Scott Armstrong (ed.): Norwell, MA: Kluwer Academic Publishers, 2001.] PollyVote applies the principle of combining forecasts to election forecasting and combines forecasts from four components: opinion polls, a prediction market, expert judgments and quantitative models. [ Cuzan, Alfred G., Armstrong, J. Scott and Jones, Randall J., [http://ssrn.com/abstract=869997 How We Computed the PollyVote] . International Journal of Applied Forecasting, Vol. 1, pp. 51-52, June 2005.]

The reasoning behind using multiple indicators is also laid out in a book by Cass Sunstein about PollyVote, titled "Infotopia: How Many Minds Produce Knowledge". [Sunstein, Cass R. (2006) [http://books.google.com/books?id=2LW1-5E7jsQC&pg=PA40&vq=pollyvote&dq=infotopia+how+many+minds+produce+knowledge&source=gbs_search_s&sig=ACfU3U2bmC23HYKaAABHKEtoM5Opn5r8SQ#PPA40,M1 Infotopia: How Many Minds Produce Knowledge] , Oxford University Press.]

Polls

PollyVote uses the RealClearPolitics poll average to calculate the Republican share of the two-party vote. Averaging these poll results has been shown to reduce the forecast error. [ Alfred G. Cuzan, J. Scott Armstrong, and Randall Jones, [http://www.forecastingprinciples.com/PollyVote/index.php/pollys-archive/polly-2004.html "Combining Methods to Forecast the 2004 Presidential Election: The PollyVote"] ]

Furthermore, evidence from the literature shows that early polls are not reliable in predicting election outcomes. In an attempt to react against high uncertainties in early phases of the election campaign, PollyVote damps poll results. It has been shown that damped polls provide more reliable forecasts. [Campbell J. E. (1996), "Polls and Votes: The Trial-Heat Presidential Election Forecasting Model, Certainty, and Political Campaigns," American Politics Quarterly, 24 (4), pp.408-433.]

Expert predictions

PollyVote analyzes forecasts from a group of experts every quarter.

Prediction markets

Prediction markets have been shown to be more accurate than traditional polls. [Joyce E. Berg, Forrest D. Nelson, Thomas A. Rietz: [http://www.biz.uiowa.edu/faculty/trietz/papers/long%20run%20accuracy.pdf "Prediction Market Accuracy in the Long Run"] , January 2008.] In its forecast, PollyVote incorporates predictions of the Iowa Electronic Markets, calculating a 7-day rolling average of the IEM prices. It should be noted that the Iowa Electronic Markets also incorporates the Pollyvote prediction model, through market participants' access to the Pollyvote output.

Quantitative models

PollyVote incorporates forecasts from quantitative models, mostly regression models.

PollyVote in the news

As the purpose of PollyVote during fall 2008 is to provide a timely prediction related to the presidential election, it would seem likely that PollyVote's numerical predictions would be cited in the news press. However, a Google news search on October 9, 2008 provides no mainstream news citations. [A Google news search on October 9, 2008 provided no mainstream news citations, while it found the Wall Street Journal blog entry by Cialik which reported about the PollyVote system.]

References

External links

* [http://www.pollyvote.com Official Site]