A Characterization of Sequential Equilibrium through $\varepsilon$-Perfect $\gamma$-Sequential Equilibrium with Local Sequential Rationality and Its Computation
Year: 2025
Type: preprint
Abstract: Sequential equilibrium requires a consistent assessment and sequential rationality, where the consistent assessment emerges from a convergent sequence of totally mixed behavioral strategies and associated beliefs. However, the original definition lacks explicit guidance on constructing such convergent sequences. To overcome this difficulty, this paper presents a characterization of sequential equilibrium by introducing $\varepsilon$-perfect $\gamma$-sequential equilibrium with local sequential rationality. For any $\gamma>0$, we establish a perfect $\gamma$-sequential equilibrium as a limit point of a sequence of $\varepsilon_k$-perfect $\gamma$-sequential equilibrium with $\varepsilon_k\to 0$. A sequential equilibrium is then derived from a limit point of a sequence of perfect $\gamma_q$-sequential equilibrium with $\gamma_q\to 0$. This characterization systematizes the construction of convergent sequences and enables the analytical determination of sequential equilibria and the development of a polynomial system serving as a necessary and sufficient condition for $\varepsilon$-perfect $\gamma$-sequential equilibrium. Exploiting the characterization, we develop a differentiable path-following method to compute a sequential equilibrium.
Authors: Yiyin Cao, Chuangyin Dang
Language: English
Topic: Game Theory and Applications
Field: Decision Sciences
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W6979296857
Cites:
Cited by:
Related to: