## Supplementary Material 

The Supplementary Material includes the following: 

• Supplementary Notes 

– Wager-Probability Relationship under Prospect and Expected Utility The- ories 

– Quantitative Testing of Alternative Models 

• Supplementary Methods: Weekly Pre-Survey 

• Supplementary Tables 

– Table S1: Average communication rates for chain and complete networks 

## Supplementary Notes 

– Table S2: NFL games used in experiment 

– Table S3: Discussion participant demographics 

– Table S4: Nonparametric testing of experimental data 

## Wager-Probability Relationship under Prospect and Expected Utility Theories 

We show that the wager is a convex function of the subjective probability in a binary gamble in which one can wager any part of an initial bonus as in our experiment. We denote the bonus by w$_{0}$ and the wager by w . If the bet is successful, then one 

