A donation may have ambiguous costs or ambiguous benefits. Behavior in a laboratory experiment suggests that individuals use this ambiguity strategically as a moral wiggle room to act less generously without feeling guilty. Such excuse-driven behavior is more pronounced when the costs of a...

In prosocial decisions, decision-makers are inherently uncertain about how their decisions impact others’ utility – we call this interpersonal uncertainty. We show that people’s response to interpersonal uncertainty shapes well-known patterns of prosocial behavior. First, using standard...

The ultimatum game is a sequential-move bargaining game in which a “giver” offers a “taker” a share of a monetary pie. The predicted subgame perfect equilibrium is for rational givers to offer the smallest possible share, and for rational takers to accept. Experimental trials conducted...

We conducted a set of experiments to compare the effect of ambiguity in single person decisions and games. Our results suggest that ambiguity has a bigger impact in games than in ball and urn problems. We find that ambiguity has the opposite effect in games of strategic substitutes and...

We report the results from a set of experiments conducted to test the effect of ambiguity on individual behaviour in games of strategic complements and strategic substitutes. We test whether subjects' perception of ambiguity differs when faced by a local opponent as opposed to a foreign one....

Two partners try to dissolve a partnership that owns an asset of ambiguous value, where the value is determined ex post by a draw from an Ellsberg urn. In a within-subject experiment, subjects make decisions in three different bargaining mechanisms: unstructured bargaining, the Texas shoot-out,...

Absentmindedness is a special case of imperfect recall which according to Piccione and Rubinstein (1997a) leads to time inconsistencies. Aumann, Hart and Perry (1997a) question their argument and show how dynamic inconsistencies can be resolved. The present paper explores this issue from a...

This paper explores three aspects of strategic uncertainty: its relation to risk, predictability of behavior and subjective beliefs of players. In a laboratory experiment we measure subjects' certainty equivalents for three coordination games and one lottery. Behavior in coordination games is...

We introduce a simple procedure to be used for selecting the strategies most likely to be played by inexperienced agents who interact in one shot 2x2 games. We start with an axiomatic description of a function that may capture players' beliefs. Various proposals connected with the concept of...

We run an experiment that gives subjects the opportunity to hedge away ambiguity in an Ellsberg-style experiment. Subjects are asked to make two bets on the same draw from an ambiguous urn, with a coin flip deciding which bet is paid. By modifying the timing of the draw, coin flip, and decision,...