Enjoy the silence: an experiment on truth-telling

We analyze experimentally two sender–receiver games with conflictive preferences. In the first game, the sender can choose to tell the truth, to lie, or to remain silent. The latter strategy is costly. In the second game, the receiver must decide additionally whether or not to costly punish the sender after having observed the history of the game. We investigate the existence of two kinds of social preferences: lying aversion and preference for truth-telling. In the first game, senders tell the truth more often than predicted by the sequential equilibrium analysis, they remain silent frequently, and there exists a positive correlation between the probability of being truthful and the probability of remaining silent. Our main experimental result for the extended game shows that those subjects who punish the sender with a high probability after being deceived are precisely those who send fewer but more truthful messages. Finally, we solve for the Perfect Bayesian Nash Equilibria of a reduced form of the baseline game with two types of senders. The equilibrium predictions obtained suggest that the observed excessive truth-telling in the baseline game can be explained by lying aversion but not by a preference for truth-telling.

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Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users. Financial support through the Ramón y Cajal program of the Spanish Ministry of Education and Science is gratefully acknowledged. This work was initiated while the author was working at Maastricht University.     

Classification of natural language messages using a coordination game

The role of natural language communication in economic exchange has been the focus of substantial experimental analysis. Recently, scholars have taken the important step of investigating whether certain types of communication (e.g., promises) might affect decisions differently than other types of communication. This requires classifying natural language messages. Unfortunately, no broadly-accepted method is available for this purpose. We here describe a coordination game for classification of natural language messages. The game is similar in spirit to the “ESP” game that has proven successful for the classification of tens of millions of internet images. We compare our approach to self-classification as well as to classifications based on a standard content analysis. We argue that our classification game has advantages over those alternative approaches, and that these advantages might stem from the salient rewards earned by our game’s participants.     

Do voluntary commitment mechanisms improve welfare? The effect of mandatory and voluntary oaths in a social dilemma

We investigate whether oaths can enforce property rights in a social dilemma and increase welfare. We examine the impact of mandatory and voluntary oaths in a laboratory experiment where individuals can produce wealth, protect accumulated wealth, and take wealth from others. Individuals are more productive when oaths are mandatory compared to a no-oath environment. Subjects’ voluntary signing oaths behave similarly to those who sign a mandatory oath. When the oath is voluntary, nonoath-taking individuals engage in nonproductive behavior, negating the positive impact from the voluntary oath. Our results show that altering commitment mechanisms can result in varying welfare levels.     

Is There a Hold‐up Problem?

We report on a hold‐up experiment in which unilateral investment is followed by bilateral bargaining according to Nash’s demand game. Without communication, investment is low and coordination is poor. Unilateral communication facilitates coordination, but not perfectly. Successful coordination predominantly entails “fair” outcomes. Perhaps surprisingly, sellers (investors) do at least as well under buyer communication as under seller communication.     

Strategy-proofness in experimental matching markets

We introduce two novel matching mechanisms, Reverse Top Trading Cycles (RTTC) and Reverse Deferred Acceptance (RDA), with the purpose of challenging the idea that the theoretical property of strategy-proofness induces high rates of truth-telling in economic experiments. RTTC and RDA are identical to the celebrated Top Trading Cycles (TTC) and Deferred Acceptance (DA) mechanisms, respectively, in all their theoretical properties except that their dominant-strategy equilibrium is to report one’s preferences in the order opposite to the way they were induced. With the focal truth-telling strategy being out of equilibrium, we are able to perform a clear measurement of how much of the truth-telling reported for strategy-proof mechanisms is compatible with rational behaviour and how much of it is caused by confused decision-makers following a default, focal strategy without understanding the structure of the game. In a school-allocation setting, we find that roughly half of the observed truth-telling under TTC and DA is the result of naïve (non-strategic) behaviour. Only 14–31% of the participants choose actions in RTTC and RDA that are compatible with rational behaviour. Furthermore, by looking at the responses of those seemingly rational participants in control tasks, it becomes clear that most lack a basic understanding of the incentives of the game. We argue that the use of a default option, confusion and other behavioural biases account for the vast majority of truthful play in both TTC and DA in laboratory experiments.

     

THE REVELATION OF INFORMATION THROUGH THE ELECTORAL PROCESS: AN EXPLORATORY ANALYSIS*

This paper investigates the incentives for candidates to make informative campaign speeches concerning their policy intentions. Electoral competition is modeled as a game of communication in which candidates’policy preferences are private information and they compete by making pre-electoral policy announcements. An equilibrium is shown to exist in which candidates reveal their true policy intentions. We find that campaign messages are more likely to be informative, the less powerful is the elected office, the more attractive are candidates’opportunities outside of office, and the more uniform are candidates’prior beliefs as to the median voter's preferred policy.     

Repetition, Communication, and Coordination Failure

We examine repetition as an institution that affects coordination failure in a game with and without pre-play communication. We use probit regression with random effects to test hypotheses regarding the frequency and form of coordination failure in the presence of repeated play versus one-shot games. Our results indicate that repetition without pre-play communication results in a lower frequency of coordination failure relative to one-shot game outcomes. This result is reversed when pre-play communication is allowed. Our evidence also suggests that repeated play coordination failures tend to be suboptimal Nash equilibria, whereas one-shot game coordination failures are disequilibria regardless of the presence of pre-play communication.     

Perfect communication equilibria in repeated games with imperfect monitoring

This paper introduces an equilibrium concept called perfect communication equilibrium for repeated games with imperfect private monitoring. This concept is a refinement of Myerson's [Myerson, R.B., 1982. Optimal coordination mechanisms in generalized principal agent problems, J. Math. Econ. 10, 67–81] communication equilibrium. A communication equilibrium is perfect if it induces a communication equilibrium of the continuation game, after every history of messages of the mediator. We provide a characterization of the set of corresponding equilibrium payoffs and derive a Folk Theorem for discounted repeated games with imperfect private monitoring.     

Perfect communication equilibria in repeated games with imperfect monitoring

This paper introduces an equilibrium concept called perfect communication equilibrium for repeated games with imperfect private monitoring. This concept is a refinement of Myerson's [Myerson, R.B., 1982. Optimal coordination mechanisms in generalized principal agent problems, J. Math. Econ. 10, 67–81] communication equilibrium. A communication equilibrium is perfect if it induces a communication equilibrium of the continuation game, after every history of messages of the mediator. We provide a characterization of the set of corresponding equilibrium payoffs and derive a Folk Theorem for discounted repeated games with imperfect private monitoring.     

Overcoming coordination failure using a mechanism based on gradualism and endogeneity

We examine three tools that can enhance coordination success in a repeated multiple-choice coordination game. Gradualism means that the game starts as an easy coordination problem and moves gradually to a more difficult one. The Endogenous Ascending mechanism implies that a gradual increase in the upper bound of coordination occurs only if coordination with the Pareto superior equilibrium in a stage game is attained. The Endogenous Descending mechanism requires that when the game’s participants fail to coordinate, the level of the next coordination game be adjusted such that the game becomes simpler. We show that gradualism may not always work, but in such instances, its effect can be reinforced by endogeneity. Our laboratory experiment provides evidence that a mechanism that combines three tools, herein termed the “Gradualism with Endogenous Ascending and Descending (GEAD)” mechanism, works well. We discuss how the GEAD mechanism can be applied to real-life situations that suffer from coordination failure.     

Promises and lies: can observers detect deception in written messages

We design a laboratory experiment to examine predictions of trustworthiness in a novel three-person trust game. We investigate whether and why observers of the game can predict the trustworthiness of hand-written communications. Observers report their perception of the trustworthiness of messages, and make predictions about the senders’ behavior. Using observers’ decisions, we are able to classify messages as “promises” or “empty talk.” Drawing from substantial previous research, we hypothesize that certain factors influence whether a sender is likely to honor a message and/or whether an observer perceives the message as likely to behonored: the mention of money; the use of encompassing words; and message length. We find that observers have more trust in longer messages and “promises”; promises that mention money are significantly more likely to be broken; and observers trust equally in promises that do and do not mention money. Overall, observers perform slightly better than chance at predicting whether a message will be honored. We attribute this result to observers’ ability to distinguish promises from empty talk, and to trust promises more than empty talk. However, within each of these two categories, observers are unable to discern between messages that senders will honor from those that they will not.     

Perturbed communication games with honest senders and naive receivers

This paper studies communication games in which the sender is possibly honest (tells the truth) and the receiver is possibly naive (follows messages as if truthful). The characterization of message-monotone equilibria in the perturbed games explain several important aspects of strategic communication including sender exaggeration, receiver skepticism and message clustering. Surprisingly, the strategic receiver may respond to more aggressive claims with more moderate actions. In the limit as the probabilities of the non-strategic players approach zero, (i) the limit equilibrium corresponds to a most-informative equilibrium of the limit (Crawford-Sobel) game; (ii) only the top messages are sent.     

Equilibria under deferred acceptance: Dropping strategies,filled positions,and welfare

We study many-to-one matching markets where hospitals have responsive preferences over students. We study the game induced by the student-optimal stable matching mechanism. We assume that students play their weakly dominant strategy of truth-telling.Roth and Sotomayor (1990) showed that equilibrium outcomes can be unstable. We prove that any stable matching is obtained in some equilibrium. We also show that the exhaustive class of dropping strategies does not necessarily generate the full set of equilibrium outcomes. Finally, we find that the ‘rural hospital theorem’ cannot be extended to the set of equilibrium outcomes and that welfare levels are in general unrelated to the set of stable matchings. Two important consequences are that, contrary to one-to-one matching markets, (a) filled positions depend on the equilibrium that is reached and (b) welfare levels are not bounded by the optimal stable matchings (with respect to the true preferences).     

Credible communication and cooperation: Experimental evidence from multi-stage Games

It is well known that communication often serves as a facilitator for cooperation in static games. Yet, communication can serve entirely different purposes in dynamic settings as communication during the game may work as a means for renegotiation, potentially undermining the credibility of cooperative strategies. To explore this issue, this paper experimentally investigates cooperation and non-binding communication in a two-stage game. More specifically, two treatments are considered: one with only pre-play communication and one where subjects can also communicate intra-play between the stages of the game. The results highlight a nontrivial difference concerning the effects of pre-play communication between the two treatments. Sending or receiving pre-play messages has a positive and significant effect on cooperation if there is no possibility of intra-play communication. However, this effect is significantly reduced when when intra-play communication is allowed. The results suggest that the credibility of pre-play messages may depend crucially on future communication opportunities.     

Incomplete information and singleton cores in matching markets

We study ordinal Bayesian Nash equilibria of stable mechanisms in centralized matching markets under incomplete information. We show that truth-telling is an ordinal Bayesian Nash equilibrium of the revelation game induced by a common belief and a stable mechanism if and only if all the profiles in the support of the common belief have singleton cores. Our result matches the observations of Roth and Peranson [The redesign of the matching market for American physicians: some engineering aspects of economic design, Amer. Econ. Rev. 89 (1999) 748-780] in the National Resident Matching Program (NRMP) in the United States: (i) the cores of the profiles submitted to the clearinghouse are small and (ii) while truth-telling is not a dominant strategy most participants in the NRMP truthfully reveal their preferences.     

Money or friends: Social identity and deception in networks

Strategic communication occurs in virtually all committee decision environments. Theory suggests that small differences in monetary incentives between committee members can leave deception a strategically optimal decision (Crawford and Sobel, 1982; Galeotti et al., 2013). At the same time, in natural environments social incentives can also play an important role in determining the way people share or withhold truthful information. Unfortunately, little is known about how monetary and social incentives interact to determine truth-telling. We investigate this issue by first building a novel model and then testing its equilibrium predictions using laboratory data. In the absence of social identity, the model׳s predictions are supported: there is more truthful communication between those who share monetary incentives than those who do not. We find that the effect of identity is asymmetric: sharing the same identity does not promote truth-telling but holding different identities reduces truthfulness. Overall, as compared to environments lacking social identity, committees with both monetary and social incentives exhibit truthful communication substantially less frequently.     

Communication, Risk, and Efficiency in Games

This paper uses curb sets to study the evolution of effective pre-play communication in games where a single communication round precedes a simultaneous-move, complete-information game. It is shown that the effectiveness of one-sided pre-play communication is inversely related to risk in the underlying game, and to the size of the message space. If messages have somea prioriinformation content, then multi-sided communication is more effective than one-sided communication; i.e., risk and the size of the message space play no role.Journal of Economic LiteratureClassification Number: C72.     

Not quite the best response: truth-telling,strategy-proof matching,and the manipulation of others

Following the advice of economists, school choice programs around the world have lately been adopting strategy-proof mechanisms. However, experimental evidence presents a high variation of truth-telling rates for strategy-proof mechanisms. We crash test the connection between the strategy-proofness of the mechanism and truth-telling. We employ a within-subjects design by making subjects take two simultaneous decisions: one with no strategic uncertainty and one with some uncertainty and partial information about the strategies of other players. We find that providing information about the out-of-equilibrium strategies played by others has a negative and significant effect on truth-telling rates. That is, most participants in our within-subjects design try and fail to best-respond to changes in the environment. We also find that more sophisticated subjects are more likely to play the dominant strategy (truth-telling) across all the treatments. These results have potentially important implications for the design of markets based on strategy-proof matching mechanisms.     

Licensing process innovations when losersʼ messages determine royalty rates

We consider a licensing mechanism for process innovations that awards a limited number of unrestricted licenses to those firms that report the highest cost reductions, combined with royalty licenses to others. Firmsʼ messages are dual signals of their cost reductions: the message of those who win an unrestricted license signals their cost reduction to rival firms, while losersʼ messages influence the royalty rate set by the innovator. We explain why a sufficiently high threshold level for awarding the unrestricted license is essential to induce truth-telling, show that the innovator generally benefits from the proposed mechanism, and derive conditions for implementability by a modified second-price auction.     

Communication and coordination in the laboratory collective resistance game

This paper presents a laboratory collective resistance (CR) game to study how different forms of non-binding communication among responders can help coordinate their collective resistance against a leader who transgresses against them. Contrary to the predictions of analysis based on purely self-regarding preferences, we find that non-binding communication about intended resistance increases the incidence of no transgression even in the one-shot laboratory CR game. In particular, we find that the incidence of no transgression increases from 7 percent with no communication up to 25–37 percent depending on whether communication occurs before or after the leader’s transgression decision. Responders’ messages are different when the leaders can observe them, and the leaders use the observed messages to target specific responders for transgression.

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Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users.