Multiscale Exit-Join Dynamics: Tactical Consensus and Strategic Coalition Formation

2026-06-18

AI Summary

This study investigates the co-evolution of coalition structures in multi-agent systems through the interplay between tactical consensus and strategic reconfiguration, with a focus on endogenous value generation, switching frictions, and structural stability. To this end, the work proposes a fast-slow coupled multiscale model that integrates DeGroot-style consensus dynamics—yielding transferable coalition values—with incentive-based exit-entrance mechanisms, thereby unifying tactical information aggregation and strategic coalition restructuring for the first time. By synthesizing the Aumann-Dreze payoff rule, multiscale dynamical systems, and fixed-point theory, the paper establishes the existence of equilibria under the coupled dynamics and uncovers an “instability-consensus paradox”: while low switching barriers impede strategic convergence, they enhance global tactical consensus. The study further introduces a novel mechanism leveraging cognitive barriers to sustain stable coalitions.

Abstract

This paper develops a multiscale model of coalition formation in which strategic exit-and-join decisions are coupled with tactical consensus dynamics inside coalitions. Coalition value is generated endogenously from within-coalition information aggregation, while Aumann-Dreze payoffs, switching frictions, and acceptance rules govern strategic reconfiguration. The framework introduces a fast-slow architecture in which transferable coalition value emerges from DeGroot-style consensus processes, while coalition structures evolve through incentive-driven exit-and-join dynamics. The analysis characterizes joint tactical-strategic equilibria, conditions for tactical and strategic unanimity, segregation, polarization, and cognitive barriers that sustain stable coalition structures. A fixed-point characterization and existence results are established for the coupled dynamics. Numerical experiments reveal an instability-consensus paradox: low or negative switching barriers may prevent strategic convergence while simultaneously promoting temporal mixing sufficient to achieve global tactical consensus. The results provide a unified perspective on coalition formation, consensus dynamics, information aggregation, and strategic stability in multi-agent systems.

Problem

• coalition formation
• consensus dynamics
• multi-agent systems
• strategic stability
• information aggregation

Innovation

• multiscale dynamics
• coalition formation
• consensus
• exit-join decisions
• strategic stability