1. Combinatorial Prediction Markets Robin Hanson Associate Professor of Economics, GMU

2. Forecasting Institutions Forecasts On Requested Topics Edits & Suggestions By Contributors

5. Combo Betting Win Place Show Not Not Not Yoopick Facebook Application Win Place Show All outcomes

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7. US President Decision Markets Politi metrics .com

8. PAM Scenario Saudi Arabian 100 75 125 1 03 2 03 3 03 4 03 1 04 2 04 65 35 70 30 30 35 25 10 15 40 35 10 100 94 Economic Health New Price < IQcs4 03 85 Return to Focus ? Trade SAum3 03 105-125 No Trade Exit Issue Max Up Max Dn 10% Dn 10% Up You Pick 62.47% Buy Sell > IQcs4 03 85 Payoffs: 68.72% 56.79% 48.54% 95.13% 22.98% +$2.74 -$15.34 +$34.74 $0.00 $0.00 -$2.61 -2.04 -$3.28 -$85.18 -$120.74 +$2.74 65 +$26.02 +1.43 +$96.61 & If 65% Ave. pay < 85 Select $0.00 +0.34 -$1.07 -$19.72 -$1.12 -$6.31 -$22.22 % Update Execute a Trade ? Return to Form Execute Abort trade if price has changed? If US military involvement in Saudi Arabia in 3 rd Quarter 2003 is not between 105 and 125, this trade is null and void. Otherwise, if Iraq civil stability in 4 th Quarter 2003 is below 85, then I will receive $1.43, but if it is not below 85, I will pay $2.04.

9. Imagine A Dashboard Ave. Worth: $12,459 Us Them A Them B Base Price $240 $187 $320 Ship Date May ’09 Mar ’09 July ’09 Features Autozoop 38% 69% 15% Fizzywoo 59% 8% 43% Unit Sales Total 120K 148K 97K Base model 82K 65K 88K Via internet 43K 12K 73K Promotion Magazine $30K $50K $3K Circulars $45 $34K $39K

10. Ask For Detail Ave.Worth: $12,459 Us Them A Them B Base Price $240 $187 $320 Ship Date May ’09 Mar ’09 July ’09 Features Autozoop 38% 69% 15% Fizzywoo 59% 8% 43% Unit Sales Total 120K 148K 97K Base model 82K 65K 88K Via internet 43K 12K 73K Promotion Magazine $30K $50K $3K Circulars $45 $34K $39K J F M A M J J A S O N D 2009 2010 Them B Ship Date

11. Make An Edit Ave. Worth: $12,459 Us Them A Them B Base Price $240 $187 $320 Ship Date May ’09 Mar ’09 July ’09 Features Autozoop 40% 69% 15% Fizzywoo 59% 8% 43% Unit Sales Total 120K 148K 97K Base model 82K 65K 88K Via internet 43K 12K 73K Promotion Magazine $30K $50K $3K Circulars $45 $34K $39K If We Have Autozoop, you gain $53 But if We Don’t Have It You lose $78. OK?

12. Make an Assumption Ave. Worth: $10,724 Scenario: 15% Us Them A Them B Base Price $240 $187 $253 Ship Date Apr ’09 Mar ’09 Assume Mar Features Autozoop 38% 69% 4% Fizzywoo 59% 8% 13% Unit Sales Total 120K 148K 107K Base model 82K 65K 94K Via internet 43K 12K 84K Promotion Magazine $30K $50K $17K Circulars $45 $34K $49K

13. Add 2nd Assumption Ave. Worth: $10,724 Scenario: 2.3% Us Them A Them B Base Price $240 $187 $253 Ship Date Apr ’09 Mar ’09 Assume Mar Features Autozoop 38% 69% 4% Fizzywoo 59% 8% 13% Unit Sales Total 185K 148K 107K Base model 97K 65K 94K Via internet 78K 12K 84K Promotion Magazine Assume $40K $50K $17K Circulars $45 $34K $49K

14. Edit As Before Ave. Worth: $10,724 Scenario: 2.3% Us Them A Them B Base Price $240 $187 $253 Ship Date Apr ’09 Mar ’09 Assume Mar Features Autozoop 42% 69% 4% Fizzywoo 59% 8% 13% Unit Sales Total 185K 148K 107K Base model 97K 65K 94K Via internet 78K 12K 84K Promotion Magazine Assume $40K $50K $17K Circulars $45 $34K $49K If we have Autozoop, you gain $53 But if we don’t have it You lose $78. OK?

16. Combo Market Maker Best of 5 Mechs 3 subjects, 7 prices, 5 minutes 6 subjects, 256 prices, 5 minutes

18. MSR Info vs. Time – 7 Prices 0 5 10 15 Minutes 0 -1 1 % Info Agg. = KL(prices,group) KL(uniform,group) 1-

19. MSR Info vs. Time – 255 prices 0 5 10 15 Minutes 0 -1 1 % Info Agg. = KL(prices,group) KL(uniform,group) 1-

21. A Simple Implementation States + - LISP: http://hanson.gmu.edu/mktscore-prototype.html Prices User Assets $1 if A&B $1 if B + q 1 - q 2 f 1 >1 f 2 <1 A B

22. A Simple Implementation States Prices User Assets A&B  A&B