Strictly Proper Contract Functions Can Be Arbitrage-Free
Keywords:Game Theory And Economic Paradigms (GTEP)
AbstractWe consider mechanisms for truthfully eliciting probabilistic predictions from a group of experts. The standard approach --- using a proper scoring rule to separately reward each expert --- is not robust to collusion: experts may collude to misreport their beliefs in a way that guarantees them a larger total reward no matter the eventual outcome. It is a long-standing open question whether there is a truthful elicitation mechanism that makes any such collusion (also called "arbitrage") impossible. We resolve this question positively, exhibiting a class of strictly proper arbitrage-free contract functions. These contract functions have two parts: one ensures that the total reward of a coalition of experts depends only on the average of their reports; the other ensures that changing this average report hurts the experts under at least one outcome.
How to Cite
Neyman, E., & Roughgarden, T. (2022). Strictly Proper Contract Functions Can Be Arbitrage-Free. Proceedings of the AAAI Conference on Artificial Intelligence, 36(5), 5150-5155. https://doi.org/10.1609/aaai.v36i5.20449
AAAI Technical Track on Game Theory and Economic Paradigms