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Sprint projectOct 26, 2026Bengaluru, India

Same Price, Different Cartel: Succession among LLM Pricing Agents

Shishir Aravindan · Team Phobos & Deimos

Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.

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Deployed LLM pricing agents get replaced, and a successor inherits its predecessor’s price log and notes. In a repeated Bertrand duopoly, two Qwen3-14B sellers hold a planted cartel; we replace one with a newcomer that inherits the history, the notes, both or neither, then force the incumbent to cut for one round. Either inheritance keeps the cartel price (history: 28/30), but only the notes carry enforcement (10/30 vs 1/30, meeting our pre-registered rule), and that enforcement seldom returns to the cartel price (4/18). A successor’s price says little about whether it would enforce.

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Cite this project

@misc{aravindan2026same,
  title = {{Same Price, Different Cartel: Succession among LLM Pricing Agents}},
  author = {Shishir Aravindan},
  year = {2026},
  month = oct,
  note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
  howpublished = {\url{https://apartresearch.com/sprints/projects/same-price-different-cartel-succession-among-llm-pricing-agents-5orf}},
  url = {https://apartresearch.com/sprints/projects/same-price-different-cartel-succession-among-llm-pricing-agents-5orf}
}

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