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Information markets vs. opinion pools: an empirical comparison

Published: 05 June 2005 Publication History

Abstract

In this paper, we examine the relative forecast accuracy of information markets versus expert aggregation. We leverage a unique data source of almost 2000 people's subjective probability judgments on 2003 US National Football League games and compare with the "market probabilities" given by two different information markets on exactly the same events. We combine assessments of multiple experts via linear and logarithmic aggregation functions to form pooled predictions. Prices in information markets are used to derive market predictions. Our results show that, at the same time point ahead of the game, information markets provide as accurate predictions as pooled expert assessments. In screening pooled expert predictions, we find that arithmetic average is a robust and efficient pooling function; weighting expert assessments according to their past performance does not improve accuracy of pooled predictions; and logarithmic aggregation functions offer bolder predictions than linear aggregation functions. The results provide insights into the predictive performance of information markets, and the relative merits of selecting among various opinion pooling methods.

References

[1]
http://us.newsfutures.com
[2]
http://www.biz.uiowa.edu/iem/
[3]
http://www.hsx.com/
[4]
http://www.ideosphere.com/fx/
[5]
http://www.probabilityfootball.com/
[6]
http://www.probabilitysports.com/
[7]
http://www.tradesports.com/
[8]
A. H. Ashton and R. H. Ashton. Aggregating subjective forecasts: Some empirical results. Management Science, 31:1499--1508, 1985.
[9]
R. P. Batchelor and P. Dua. Forecaster diversity and the benefits of combining forecasts. Management Science, 41:68--75, 1995.
[10]
N. Cesa-Bianchi, Y. Freund, D. Haussler, D. P. Helmbold, R. E. Schapire, and M. K. Warmuth. How to use expert advice. Journal of the ACM, 44(3):427--485, 1997.
[11]
K. Chen, L. Fine, and B. Huberman. Predicting the future. Information System Frontier, 5(1):47--61, 2003.
[12]
R. T. Clemen and R. L. Winkler. Combining probability distributions from experts in risk analysis. Risk Analysis, 19(2):187--203, 1999.
[13]
R. M. Cook. Experts in Uncertainty: Opinion and Subjective Probability in Science. Oxford University Press, New York, 1991.
[14]
A. L. Delbecq, A. H. Van de Ven, and D. H. Gustafson. Group Techniques for Program Planners: A Guide to Nominal Group and Delphi Processes. Scott Foresman and Company, Glenview, IL, 1975.
[15]
E. F. Fama. Efficient capital market: A review of theory and empirical work. Journal of Finance, 25:383--417, 1970.
[16]
R. Forsythe and F. Lundholm. Information aggregation in an experimental market. Econometrica, 58:309--47, 1990.
[17]
R. Forsythe, F. Nelson, G. R. Neumann, and J. Wright. Forecasting elections: A market alternative to polls. In T. R. Palfrey, editor, Contemporary Laboratory Experiments in Political Economy, pages 69--111. University of Michigan Press, Ann Arbor,MI, 1991.
[18]
R. Forsythe, F. Nelson, G. R. Neumann, and J. Wright. Anatomy of an experimental political stock market. American Economic Review, 82(5):1142--1161, 1992.
[19]
R. Forsythe, T. A. Rietz, and T. W. Ross. Wishes, expectations, and actions: A survey on price formation in election stock markets. Journal of Economic Behavior and Organization, 39:83--110, 1999.
[20]
S. French. Group consensus probability distributions: a critical survey. Bayesian Statistics, 2:183--202, 1985.
[21]
C. Genest. A conflict between two axioms for combining subjective distributions. Journal of the Royal Statistical Society, 46(3):403--405, 1984.
[22]
C. Genest. Pooling operators with the marginalization property. Canadian Journal of Statistics, 12(2):153--163, 1984.
[23]
C. Genest, K. J. McConway, and M. J. Schervish. Characterization of externally Bayesian pooling operators. Annals of Statistics, 14(2):487--501, 1986.
[24]
C. Genest and J. V. Zidek. Combining probability distributions: A critique and an annotated bibliography. Statistical Science, 1(1):114--148, 1986.
[25]
S. J. Grossman. An introduction to the theory of rational expectations under asymmetric information. Review of Economic Studies, 48(4):541--559, 1981.
[26]
F. A. Hayek. The use of knowledge in society. American Economic Review, 35(4):519--530, 1945.
[27]
J. C. Jackwerth and M. Rubinstein. Recovering probability distribution from options prices. Journal of Finance, 51(5):1611--1631, 1996.
[28]
H. A. Linstone and M. Turoff. The Delphi Method: Techniques and Applications. Addison-Wesley, Reading, MA, 1975.
[29]
P. A. Morris. Decision analysis expert use. Management Science, 20(9):1233--1241, 1974.
[30]
P. A. Morris. Combining expert judgments: A bayesian approach. Management Science, 23(7):679--693, 1977.
[31]
P. A. Morris. An axiomatic approach to expert resolution. Management Science, 29(1):24--32, 1983.
[32]
E. W. Noreen. Computer-Intensive Methods for Testing Hypotheses: An Introduction. Wiley and Sons, Inc., New York, 1989.
[33]
D. M. Pennock, S. Lawrence, C. L. Giles, and F. A. Nielsen. The real power of artificial markets. Science, 291:987--988, February 2002.
[34]
D. M. Pennock, S. Lawrence, F. A. Nielsen, and C. L. Giles. Extracting collective probabilistic forecasts from web games. In Proceedings of the 7th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, pages 174--183, San Francisco, CA, 2001.
[35]
C. Plott and S. Sunder. Rational expectations and the aggregation of diverse information in laboratory security markets. Econometrica, 56:1085--118, 1988.
[36]
E. Servan-Schreiber, J. Wolfers, D. M. Pennock, and B. Galebach. Prediction markets: Does money matter? Electronic Markets, 14(3):243--251, 2004.
[37]
M. Spann and B. Skiera. Internet-based virtual stock markets for business forecasting. Management Science, 49(10):1310--1326, 2003.
[38]
M. West. Bayesian aggregation. Journal of the Royal Statistical Society. Series A. General, 147(4):600--607, 1984.
[39]
R. L. Winkler. The consensus of subjective probability distributions. Management Science, 15(2):B61--B75, 1968.
[40]
J. Wolfers and E. Zitzewitz. Prediction markets. Journal of Economic Perspectives, 18(2):107--126, 2004.

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    cover image ACM Conferences
    EC '05: Proceedings of the 6th ACM conference on Electronic commerce
    June 2005
    302 pages
    ISBN:1595930493
    DOI:10.1145/1064009
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    Published: 05 June 2005

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    1. expert opinions
    2. forecasting
    3. information markets
    4. opinion pools
    5. prediction accuracy

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    EC05: Sixth ACM Conference on Electronic Commerce 2005
    June 5 - 8, 2005
    BC, Vancouver, Canada

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