Strategic Discontinuity in Simple and Complicated Games
2009/07/21
研討會日期 : 2009-07-21
時間 : 14:30
主講人 : 陳逸群助理教授
地點 : B110
演講者簡介 : 陳逸群教授為Ph.D. in Economics，Northwestern University (2009)。現為新加坡國立大學經濟系助理教授。其主要研究領域為Microeconomics Theory、Game Theory、Mathematical Economics、Information Economics。
演講摘要 : Economic models employ assumptions about agents' infinite hierarchies of belief. We might hope to achieve reasonable approximations by specifying only finitely many levels in the hierarchy. However, it is well known since Rubinstein (1989) that the behaviors of some fully specifi ed hierarchies can be very different from the behavior of such finite approximations. We study Harsanyi types which exhibit strategic discontinuity in simple/complicated games. Following the idea of Ely and Peski (2007), we say that a type t is n-critical, if there exists an n×n game and a sequence of types whose beliefs match those of t up to any finite order and whose interim rationalizable behaviors fail to converge to those of t. We show that every finite type is 3-critical, every common prior assigns probability 1 to 3-critical types, and moreover, 3-critical types are generic in the universal type space under the strategic topology defined in Dekel, Fudenberg, and Morris (2006). However, for any integer n≥2, there exists an n′-critical type with n′>n which is not n-critical. Consequently, the characterization of all critical types obtained by Ely and Peski (2007) necessarily involves complicated games. Finally, every type is ∞-critical.
