Scaling Multi-Agent Systems with Prospect-State Propagation

Zhimei Chen, Mu Chen, Fakhri Karray


Abstract
Current LLM-based multi-agent systems (MAS) periodically compress intermediate states to reduce inference-time token consumption, thereby attempting to incorporate more agents. However, naive scaling strategies face challenges. For example, in economic simulations, large-scale MAS typically discard semantically rich economic states, i.e., agent behavioral trajectories, which are key drivers of macroeconomic fluctuations. In this paper, we reveal a phenomenon in which agent heterogeneity gradually decreases during simulation, and propose Prospect-State Propagation for Multi-Agent Systems (PspMAS). Inspired by prospect theory, PspMAS decouples each agent’s micro state into a compact Prospect State and an expressive Semantic State. The former records psychological traces through a lightweight, parallelizable propagator and continuously injects heterogeneity into the system. The latter leverages the strong perception, reasoning, planning, and decision-making abilities of LLMs. These two components work complementarily, providing a scalable LLM-based multi-agent simulation solution.
Anthology ID:
2026.findings-emnlp.1585
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
33754–33766
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1585/
DOI:
Bibkey:
Cite (ACL):
Zhimei Chen, Mu Chen, and Fakhri Karray. 2026. Scaling Multi-Agent Systems with Prospect-State Propagation. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 33754–33766, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Scaling Multi-Agent Systems with Prospect-State Propagation (Chen et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1585.pdf