Template-type: ReDif-Paper 1.0 Author-Name: Flesch, Janos Author-workplace-name: QE Math. Economics & Game Theory, RS: GSBE ETBC, RS: GSBE Theme Conflict & Cooperation Author-Name: Herings, P. Jean-Jacques Author-workplace-name: Microeconomics & Public Economics, RS: GSBE ETBC, RS: GSBE Theme Conflict & Cooperation, RS: GSBE Theme Data-Driven Decision-Making Author-Name: Maes, Jasmine Author-workplace-name: Microeconomics & Public Economics, RS: GSBE ETBC, RS: GSBE Theme Conflict & Cooperation Author-Name: Predtetchinski, Arkadi Author-workplace-name: Microeconomics & Public Economics, RS: GSBE ETBC, RS: GSBE Theme Conflict & Cooperation Title: Subgame maxmin strategies in zero-sum stochastic games with tolerance levels Abstract: We study subgame φ-maxmin strategies in two-player zero-sum stochastic games with finite action spaces and a countable state space. Here φ denotes the tolerance function, a function which assigns a non-negative tolerated error level to every subgame. Subgame φ-maxmin strategies are strategies of the maximizing player that guarantee the lower value in every subgame within the subgame-dependent tolerance level as given by φ. First, we provide necessary and sufficient conditions for a strategy to be a subgame φ-maxmin strategy. As a special case we obtain a characterization for subgame maxmin strategies, i.e. strategies that exactly guarantee the lower value at every subgame. Secondly, we present sufficient conditions for the existence of a subgame φ-maxmin strategy. Finally, we show the possibly surprising result that the existence of subgame φ-maxmin strategies for every positive tolerance function φ is equivalent to the existence of a subgame maxmin strategy. Classification-JEL: c73 Series: GSBE Research Memoranda Creation-Date: 20180814 Number: 020 File-URL: https://cris.maastrichtuniversity.nl/ws/files/27587143/RM18020.pdf File-Format: application/pdf File-Size: 700874 Handle: Repec:unm:umagsb:2018020 DOI: 10.26481/umagsb.2018020