BE J. Theor. Econ. 2016; aop Carsten S. Nielsen and Alexander Sebald* Simple Unawareness in Dynamic Psychological Games DOI 10.1515/bejte-2015-0011 Abstract: Building on Battigalli and Dufwenberg (2009)’s framework of dynamic psychological games and the progress in the modeling of dynamic unawareness by Heifetz, Meier, and Schipper (2013a) we model and analyze the impact of asymmetric awareness in the strategic interaction of players motivated by reciprocity and guilt. Specifically we characterize extensive-form games with psychological payoffs and simple unawareness, define extensive-form rationalizability and, using this, show that unawareness has a pervasive impact on the strategic interaction of psychologi- cally motivated players. Intuitively, unawareness influences players’ beliefs con- cerning, for example, the intentions and expectations of others which in turn impacts their behavior. Keywords: unawareness, psychological payoffs, extensive-form rationalizability JEL Classification: C72, C73, D80 1 Introduction Recent lab and field evidence suggests that people not only care about the monetary consequences of their actions, but that their behavior is also driven by psychological payoffs (for example, Fehr, Kirchsteiger, and Riedl 1993; Charness and Dufwenberg 2006; Falk, Fehr, and Fischbacher 2008; Bellemare, Sebald, and Strobel 2011). Two prominent examples of psychological payoffs in the hitherto existing literature are reciprocity (for example, Rabin 1993; Dufwenberg and Kirchsteiger 2004; Falk and Fischbacher 2006) and guilt aver- sion (for example, Charness and Dufwenberg 2006; Battigalli and Dufwenberg 2007). Departing from the strictly consequentialist tradition in economics, Geanakoplos, Pearce, and Stacchetti (1989) and Battigalli and Dufwenberg *Corresponding author: Alexander Sebald, Department of Economics, University of Copenhagen, Ø ster Farimagsgade 5, Building 26, DK-1353, Copenhagen K, Denmark, E-mail:
[email protected] Carsten S.