Why Do People Keep Their Promises? An Experimental Test of Two Explanations

Abstract

Numerous psychological and economic experiments have shown that the exchange of promises greatly enhances cooperative behavior in experimental games. This paper seeks to test two theories to explain this effect. The first posits that individuals have a preference for keeping their word. The second assumes that people dislike letting down others' payoff expectations. According to the latter account, promises affect behavior only indirectly, because they lead to changes in the payoff expectations attributed to others. I conduct an experiment designed to distinguish between and test these alternative explanations. The results demonstrate that the effects of promises cannot be accounted for by changes in payoff expectations. This suggests that people have a preference for promise keeping per se.

Promises and lies: can observers detect deception in written messages

“…For example, Charness and Dufwenberg (2006) classified 57 % of their messages from B in the (5, 5) treatment as promises; Vanberg (2008) classified 85 % of the messages as promises in No Switch and 77 % of the messages as promises in Switch. Using the same procedure as we do, Houser and Xiao (2010) found that 74 % of the B messages from Charness and Dufwenberg (2006) (5,5) experiment were categorized as promises by the evaluators in their weak promise treatment.…”

Self-Conscious or Fear of Hurting Another’s Feeling? An Experimental Investigation on Promise-Keeping

“…The first possible influence mechanism is the internalized norm mechanism. The substance of this mechanism is that making promises activates promisors' internalized norm of promise-keeping and a desire to comply with the norm of promise-keeping per se motivates individuals to keep their word and improve their level of cooperation (Kerr et al, 1997;Ellingsen and Johannesson, 2004;Vanberg, 2008;Ellingsen et al, 2010;Kawagoe and Narita, 2014;Krupka et al, 2016, etc.). That is, individuals keep their promises due to self-consciousness 1 .…”

Broken Contracts and Hidden Partnerships: Theory and Experiment

“…One is the homogeneous aversion to lying model suggested by Ellingsen and Johannesson (2004), Miettinen and Suetens (2008), and Vanberg (2008), where the model assumes that people incur a similar fixed cost in their utilities when caught lying; the other is the heterogeneous cost of lying model, where different people might incur different costs while caught lying (e.g., Gibson et al (2013)). …”

“…The literature further suggests that communication, particularly informal contract/commitment, is crucial for facilitating cooperation and improving efficiency. (see, for example Charness and Dufwenberg, 2006;Charness et al, 2012Charness and Dufwenberg, 2011;Miettinen and Suetens, 2008;Vanberg, 2008;Ellingsen and Johannesson, 2004;Kerr and Kaufman-Gilliland, 1994;Loomis, 1959;Sally, 1995). By the same token, the literature indicates that people not only strive to keep their promises, but are also averse to breaking informal contracts and lying to others.…”

“…Finally, we shed light on the empirical relevance of existing behavioral theories. In particular, we take our data to the three current competing theories: innate preference for honesty models (see, e.g., Ellingsen and Johannesson, 2004;Miettinen and Suetens, 2008;Vanberg, 2008;Gibson et al, 2013), the consequence based preference model (see, e.g., Battigalli and Dufwenberg, 2007;Battigalli et al, 2013;Charness and Dufwenberg, 2006) and simple type models (see, e.g., Hurkens and Kartik, 2009). We derive and summarize testable predictions from these theories and then compare those predictions with our experimental data.…”