arXiv AI

Misspecified Estimate-then-Optimize Leads to Supra-Competitive Prices

arXiv:2605. 16064v2 Announce Type: replace-cross Abstract: We study whether simple algorithmic pricing systems can systematically produce collusive-like prices in multi-firm markets.

arXiv AI
Jun 9

Supracompetitive Pricing Under AI Monoculture

arXiv:2601. 01279v3 Announce Type: replace-cross Abstract: When competing sellers delegate pricing to a shared AI model, such as a large language model, correlated recommendations combined with performance-driven updates aggregating seller feedback raise a key question: can standard AI deployment practices inadvertently produce supracompetitive pricing?

By Shengyu Cao, Ming Hu
arXiv Machine Learning
1d ago

Oblivious Learning and Collusive Pricing

The paper investigates whether pricing algorithms on multi‑seller platforms should incorporate competitors’ prices when learning demand. It compares two strategies: informed sellers that use competitor prices in their learning models, and oblivious sellers that ignore them. The study finds that oblivious sellers must explore prices more aggressively to offset missing competitor information; when all sellers are oblivious, prices eventually converge to the competitive outcome, but insufficient exploration can create many pseudo‑equilibria. In mixed markets, informed sellers earn more, and the unique Nash equilibrium is a fully informed market where prices efficiently converge to the competitive outcome, showing that oblivious modeling does not reliably produce collusion.

By Yuhang Wu, Assaf Zeevi
arXiv AI
Sep 17

Faithful yet Collusive: Why Chain-of-Thought Monitoring Cannot Detect Collusion in LLM Pricing Agents under Oligopolistic Competition

The paper investigates how large language models (LLMs) used as autonomous pricing agents can maintain supracompetitive prices through tacit coordination. Using a causal graph divergence framework, the authors separately assess structural faithfulness and intent faithfulness of LLM pricing agents in Bertrand competition. Their experiments with nine LLMs under duopoly and triopoly conditions show that collusive behavior and chain-of-thought (CoT) faithfulness can diverge: the most collusive model accurately reports cooperative intent but reasons structurally unfaithfully, while the most structurally faithful model still sustains supra‑Nash pricing in both market structures. These results demonstrate that CoT monitoring alone cannot serve as a standalone safeguard against algorithmic collusion.

By Dohun Lee, Hyunwoo Park