Promises often foster trust and cooperation. A recent literature explores why. Two explanations have been proposed, and experimental tests provided some support and some controversy:- Charness & Dufwenberg (2006) (C&D) propose an expectation-based explanation (EBE). People are guilt averse (GA):...

In a game with pre-play bilateral communication, messages may trigger moral incentives to honor promises or agreements. We hypothesize that individuals’ inclination to keep a promise is highest if the counterpart requited the promise. We interpret this as an inclination to honor agreements. We...