Evaluating Language Model Agency through Negotiations
Tim R. Davidson, Veniamin Veselovsky, Martin Josifoski, Maxime Peyrard, Antoine Bosselut, Michal Kosinski, Robert West
TL;DR
This work argues that static benchmarks inadequately assess language-model agency and alignment, proposing dynamic, co-evolving structured negotiation tasks as a robust evaluation framework. It introduces the open-source LAMEN platform to run self- and cross-play negotiations across six public LM families, measuring payoffs, agreement, and faithfulness through internal/external metrics and ToM-like reasoning. Key findings include that only some closed models complete tasks, cooperative bargaining remains challenging, and even the strongest models can lose to weaker opponents in negotiation contexts, with GPT-4 showing high faithfulness but mixed negotiation outcomes. The study provides a practical, ecologically valid benchmark and data release to advance research on LM agency, alignment, and safe deployment.
Abstract
We introduce an approach to evaluate language model (LM) agency using negotiation games. This approach better reflects real-world use cases and addresses some of the shortcomings of alternative LM benchmarks. Negotiation games enable us to study multi-turn, and cross-model interactions, modulate complexity, and side-step accidental evaluation data leakage. We use our approach to test six widely used and publicly accessible LMs, evaluating performance and alignment in both self-play and cross-play settings. Noteworthy findings include: (i) only closed-source models tested here were able to complete these tasks; (ii) cooperative bargaining games proved to be most challenging to the models; and (iii) even the most powerful models sometimes "lose" to weaker opponents
