2020/05/20 by Chuangyin Dang, Qi Qi, Dang, Chuangyin +3 · 1 citation
Decision Sciences · Economics, Econometrics and Finance · #Computational Complexity (cs.CC) #Computer Science and Game Theory (cs.GT) #Economic theories and models #FOS: Computer and information sciences #FOS: Economics and business #Game Theory and Applications #Game Theory and Voting Systems #Theoretical Economics (econ.TH)
paper · pdf · doi:10.48550/arxiv.2005.09836
openalex publication_date 2020/05/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider two models of computation for Tarski's order preserving function f related to fixed points in a complete lattice: the oracle function model and the polynomial function model. In both models, we find the first polynomial time algorithm for finding a Tarski's fixed point. In addition, we provide a matching oracle bound for determining the uniqueness in the oracle function model and prove it is Co-NP hard in the polynomial function model. The existence of the pure Nash equilibrium in supermodular games is proved by Tarski's fixed point theorem. Exploring the difference between supermodular games and Tarski's fixed point, we also develop the computational results for finding one pure Nash equilibrium and determining the uniqueness of the equilibrium in supermodular games.