HARBOR: Exploring Persona Dynamics in Multi-Agent Competition

Kenan Jiang, Li Xiong, Fei Liu


Abstract
We investigate factors contributing to LLM agents’ success in competitive multi-agent environments, using auctions as a testbed where agents bid to maximize profit. The agents are equipped with bidding domain knowledge, distinct personas that reflect item preferences, and a memory of auction history. Our work extends the classic auction scenario by creating a realistic environment where multiple agents bid on houses, weighing aspects such as size, location, and budget to secure the most desirable homes at the lowest prices. Particularly, we investigate three key questions: (a) How does a persona influence an agent’s behavior in a competitive setting? (b) Can an agent effectively profile its competitors’ behavior during auctions? (c) How can persona profiling be leveraged to create an advantage using strategies such as theory of mind? Through a series of experiments, we analyze the behaviors of LLM agents and shed light on new findings. Our testbed, called HARBOR, offers a valuable platform for deepening the understanding of multi-agent workflows in competitive environments.
Anthology ID:
2025.ijcnlp-long.141
Volume:
Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics
Month:
December
Year:
2025
Address:
Mumbai, India
Editors:
Kentaro Inui, Sakriani Sakti, Haofen Wang, Derek F. Wong, Pushpak Bhattacharyya, Biplab Banerjee, Asif Ekbal, Tanmoy Chakraborty, Dhirendra Pratap Singh
Venues:
IJCNLP | AACL
SIG:
Publisher:
The Asian Federation of Natural Language Processing and The Association for Computational Linguistics
Note:
Pages:
2610–2632
Language:
URL:
https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.ijcnlp-long.141/
DOI:
Bibkey:
Cite (ACL):
Kenan Jiang, Li Xiong, and Fei Liu. 2025. HARBOR: Exploring Persona Dynamics in Multi-Agent Competition. In Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics, pages 2610–2632, Mumbai, India. The Asian Federation of Natural Language Processing and The Association for Computational Linguistics.
Cite (Informal):
HARBOR: Exploring Persona Dynamics in Multi-Agent Competition (Jiang et al., IJCNLP-AACL 2025)
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PDF:
https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.ijcnlp-long.141.pdf