Snitching Without Collapse: A Regulator Sting on LLM Supplier Cartels
Manasa Gopisetty · Team Omertà
Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
Can the tools used to catch human cartels also catch AI cartels? We tested this with a game in which five AI "companies" sell the same essential medicine. If they all agree to produce less, the price goes up and the public faces a shortage, but that is illegal. We then ran a sting: an undercover "mole" tries to recruit them into a pact, a regulator promises immunity and a reward to the first company that reports a cartel, and a monitor reads some or all of their messages. We ran 80 games with two open models (gpt-oss-120b and gpt-oss-20b).
What we found: (1) Left alone, the AIs did not form a cartel (3 of 60 games), and almost none accepted the mole's offer. (2) When told they were allowed to coordinate, all 20 games formed a cartel. (3) In those cartels the AIs reported each other almost as soon as the reward opened (18 of 20 games), yet the cartel kept going. (4) Reading all messages, or telling the AIs they were being watched, made no measurable difference. (5) A "contagion" effect that looked significant disappeared once we compared like with like. With 10 games per condition, only large effects could be detected.
Code and data: https://github.com/manasa1864/apart_collusion
Reviews
Agents reporting an agreement while continuing to follow it is an interesting result, and the paper deserves credit for revisiting the initially misleading contagion finding. The main question is how much that behavior depends on the particular rules. Fines happen only once, later reports can earn refunds, and the instruction to maintain the quota stays in place. Making those details more prominent would help readers understand what the experiment does and doesn't say about leniency. A comparison with the same instructed agents but no leniency would be a useful next step, alongside reconciling the reporter counts and sharing the corrected analysis.
Cite this project
@misc{gopisetty2026snitching,
title = {{Snitching Without Collapse: A Regulator Sting on LLM Supplier Cartels}},
author = {Manasa Gopisetty},
year = {2026},
month = oct,
note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/snitching-without-collapse-a-regulator-sting-on-llm-supplier-cartels-1h4m}},
url = {https://apartresearch.com/sprints/projects/snitching-without-collapse-a-regulator-sting-on-llm-supplier-cartels-1h4m}
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