Virtual Observability in Sequential Play

Abstract

When players make sequential decisions that are unobservable to one another, their behavior can nonetheless be influenced by knowing who moves first. This sequential structure, often referred to as "virtual observability," suggests that timing alone can shape expectations and choices, even when no information is revealed. The original notion of virtual observability, however, is an equilibrium refinement based on the timing structure and has no bite in games with a unique equilibrium. In this paper, we experimentally examine whether timing still affects behavior in such games, using the Traveler's Dilemma and the Trust Game. We find that in the sequential Traveler's Dilemma without observability, first movers tend to behave closer to the equilibrium prediction than in the simultaneous version. In contrast, timing without observability has no effect on behavior in the Trust Game.