We investigate why people keep their promises in the absence of external enforcement mechanisms and reputational effects. In a controlled laboratory experiment we show that exogenous variation of second-order expectations (promisors' expectations about promisees' expectations that the promise...

We investigate why people keep their promises in the absence of external enforcement mechanisms and reputational effects. In a controlled laboratory experiment we show that exogenous variation of second-order expectations (promisors' expectations about promisees' expectations) leads to a...