Artificial Intelligence and Auction Design
This addresses auction design problems for online advertising platforms, showing incremental insights into AI-driven collusion risks.
The study examined how simple AI algorithms (Q-learning) behave in repeated auctions, finding that first-price auctions lead to tacit collusion with bids lower than values, while second-price auctions do not, and that providing information about the lowest bid to win increases competitiveness.
Motivated by online advertising auctions, we study auction design in repeated auctions played by simple Artificial Intelligence algorithms (Q-learning). We find that first-price auctions with no additional feedback lead to tacit-collusive outcomes (bids lower than values), while second-price auctions do not. We show that the difference is driven by the incentive in first-price auctions to outbid opponents by just one bid increment. This facilitates re-coordination on low bids after a phase of experimentation. We also show that providing information about lowest bid to win, as introduced by Google at the time of switch to first-price auctions, increases competitiveness of auctions.