A simpler auction format reduced LLM agents’ bid deviations in a study

In an arXiv paper, researchers tested LLM agents in auctions and matching tasks across four model families. They found that a rising-price auction format reduced bid deviations and that explaining why truthful choices were safe improved decisions. Prompts to plan through matching rounds or form beliefs about opponents worsened play overall. In auctions, better bids did not come with corresponding improvements in the agents’ short written plans.