Extending Games beyond the Finite Horizon
Kiri Sakahara, Takashi Sato
TL;DR
Extending Games beyond the Finite Horizon introduces Alternative Set Theory (AST) to model infinite-like cognitive perception in long-horizon games. It develops two perspectives on histories, Perspective View and Bird's Eye View, and analyzes payoff aggregation under three criteria Discounted/Simple Sum, Overtaking, and Limit of Means to derive new subgame-perfect equilibria. The framework resolves classic paradoxes such as Selten's chain store and Rosenthal's centipede by allowing huge indistinguishable payoffs to influence strategic choice, with dynamic consistency and huge transitivity playing key roles. Overall, the work broadens game theory's reach into ultra-long horizons by tying mathematical foundations to cognitive models of time and perception.
Abstract
This paper argues that the finite horizon paradox, where game theory contradicts intuition, stems from the limitations of standard number systems in modelling the cognitive perception of infinity. To address this issue, we propose a new framework based on Alternative Set Theory (AST). This framework represents different cognitive perspectives on a long history of events using distinct topologies. These topologies define an indiscernibility equivalence that formally treats huge, indistinguishable quantities as equivalent. This offers criterion-dependent resolutions to long-standing paradoxes, such as Selten's chain store paradox and Rosenthal's centipede game. Our framework reveals new intuitive subgame perfect equilibria, the characteristics of which depend on the chosen temporal perspective and payoff evaluation. Ultimately, by grounding its mathematical foundation in different modes of human cognition, our work expands the explanatory power of game theory for long-horizon scenarios.
