Cheap talk with multiple audiences: An experimental analysis

We examine strategic information transmission in a controlled laboratory experiment of a cheap talk game with one sender and multiple receivers. We study the change in equilibrium behavior from the addition of another audience as well as from varying the degree of conflict between the senderʼs and receiversʼ preferences. We find that, as in cheap talk games with just one receiver, information transmission is higher in games with a separating equilibrium, than in games with only a babbling equilibrium. More interestingly, we find clear evidence that the addition of another audience alters the communication between the sender and the receiver in a way consistent with the theoretical predictions. There is evidence of the presence of agents that are systematically truthful as senders and trusting as receivers: deviations from the theoretical predictions, however, tend to disappear with experience, and learning is faster precisely in the games where deviations are more pronounced.     

Reputational cheap talk with misunderstanding

We consider a cheap talk game with a sender who has a reputational concern for an ability to predict a state of the world correctly, and where receivers may misunderstand the message sent. When communication between the sender and each receiver is private, we identify an equilibrium in which the sender only discloses the least noisy information. Hence, what determines the amount of information revealed is not the absolute noise level of communication, but the extent to which the noise level may vary. The resulting threshold in transmission noise for which information is revealed may differ across receivers, but is unrelated to the quality of the information channel. When information transmission has to be public, a race to the bottom results: the cut-off level for noise of transmitted information now drops to the lowest cut-off level for any receiver in the audience.     

Whatever you say, your reputation precedes you: Observation and cheap talk in the trust game

Behavior in trust games has been linked to general notions of trust and trustworthiness, important components of social capital. In the equilibrium of a trust game, the investor does not invest, foreseeing that the allocator would keep all of the returns. We use a human-subjects experiment to test the effects of changes to the game designed to increase cooperation and efficiency. We add a pre-play stage in which the investor receives a cheap-talk message from the allocator, observes the allocator's previous decision, or both. None of these changes alter the game's theoretical predictions. We find that allowing observation results in substantially higher cooperation and efficiency, but cheap talk has little effect.     

Multidimensional cheap talk with sequential messages

This paper studies a two-dimensional cheap talk game with two senders and one receiver. The senders possess the same information and sequentially send messages about that information. In one-dimensional sequential message cheap talk games where the state space is unbounded, the information is fully transmitted under the self-serving belief, as suggested by Krishna and Morgan (2001b). However, this result depends crucially on the structure of the one-dimensional model. It generally does not hold in two-dimensional models. We consider the extended self-serving belief, which implies full information transmission even if the self-serving belief cannot work. Then, we show that the necessary and sufficient condition for the existence of the fully revealing equilibrium is that the senders have opposing-biased preferences.     

Communication in financial markets with several informed traders

This paper investigates the incentives for informed traders in financial markets to reveal their information truthfully to the public. In the model, a subset of traders receive noisy signals about the value of a risky asset. The signals are composed of a directional component (“high” vs. “low”) as well as a precision component that represents the quality of the directional component. Between trading periods, the informed agents make public announcements to the uninformed traders. With a sufficiently large number of informed traders, an equilibrium exists in which the directional components are credibly revealed, but not the precision components. Even though the informed traders retain some of their rivate information, the post-communication estimate of the asset value converges in probability to the full-information estimate as the number of informed traders increases. The paper is based on a chapter of my Ph.D. thesis at the University of Western Ontario and was circulated previously under the title “Public Communication Devices in Financial Markets.” I thank my dissertation committee Arthur Robson, Hari Govindan, and Al Slivinski for their guidance and support. I also thank Murali Agastya, Roland Benabou, Philippe Grégoire, Rick Harbaugh, Mike Peters, an anonymous referee and an associate editor, and seminar participants at various universities and conferences at which this paper was presented.     

Equilibrium selection in experimental cheap talk games

In the past, many refinements have been proposed to select equilibria in cheap talk games. Usually, these refinements were motivated by a discussion of how rational agents would reason in some particular cheap talk games. In this paper, we propose a new refinement and stability measure that is intended to predict actual behavior in a wide range of cheap talk games. According to our Average Credible Deviation Criterion (ACDC), the stability of an equilibrium is determined by the frequency and size of credible deviations. ACDC organizes the results from several cheap talk experiments in which behavior converges to equilibrium, even in cases where other criteria do not make a prediction.     

A note on one-shot public mediated talk

Lehrer and Sorin (1997, Games Econ. Behav. 20, 131–148) use a one-shot public mediated talk model to show that, given any probability distribution on the outcomes of a finite normal-form game, there exists a public mediated talk mechanism that simulates that distribution, provided the probabilities on outcomes are rational numbers. It is shown here that a minor amendment of the very same model allows a much stronger conclusion: any distribution on the outcomes, whether the probabilities are rational numbers or not, can be obtained as the outcome of a one-shot public mediated talk mechanism.     

Learning to communicate in cheap-talk games

We study learning in communication games. Our main finding is that a simple forward-looking learning rule leads to communication in a large class of games. This class is characterized by a partial-common-interest condition. In contrast, we show that a variety of purely backward looking dynamics may fail to guarantee communication. Memory is a partial substitute for looking forward: With long memory, backward-looking learning leads to communication in a class of games with perfect incentive alignment.     

Harmful lie aversion and lie discovery in noisy expert advice games

This study tests whether individuals are reluctant to tell lies, or perhaps only “harmful lies”, in a previously untested environment: an expert sending a message to a decision maker whose interpretation of that message is subject to error, i.e. a noisy sender–receiver game. In the Aligned treatment, the expert can send a “white lie” to the receiver, eliminating the negative effects of noise and improving both parties’ payoffs. In the Conflict treatment, lies are harmful and the inability to commit to truthtelling destroys all meaningful communication in equilibrium unless there is a cost of lying. In the experiment, receivers are overly trusting and experts learn to take advantage of this. As experts gain experience they tell stronger and more frequent lies in both treatments, consistent with models of reinforcement learning. The findings suggest that neither harmful nor universal lie aversion is a factor when communication is noisy, provided individuals have time to discover their personal benefits of lies.     

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.      

Markets for information: Of inefficient firewalls and efficient monopolies

In this paper we study market environments where information is costly to acquire and is also useful to potential competitors. Agents may sell, or buy, reports over the information acquired and choose their trades in the market on the basis of what they learnt. Reports are unverifiable – cheap talk messages – hence the quality of the information transmitted depends on the conflicts of interest faced by the senders. We find that, when information has a prevalent horizontal differentiation component, in equilibrium information is acquired when its costs are not too high and in that case it is also sold, though reports are typically noisy. The market for information is in most cases a monopoly, and there is underinvestment in information acquisition. We also show that regulatory interventions, in the form of firewalls, only make the inefficiency worse. Efficiency can be attained with a monopolist selling differentiated information, provided entry is blocked.     

Cost incentives for doctors: A double-edged sword

If doctors take the costs of treatment into account when prescribing medication, their objectives differ from their patients' objectives because the patients are insured. This misalignment of interests hampers communication between patient and doctor. Giving cost incentives to doctors increases welfare if (i) the doctor's examination technology is sufficiently good or (ii) (marginal) costs of treatment are high enough. If the planner can costlessly choose the extent to which doctors take costs into account, he will opt for less than 100%. Optimal health care systems should implement different degrees of cost incentives depending on type of disease and/or doctor.     

The role of strategic uncertainty in games: An experimental study of cheap talk and contracts in the Nash demand game

We utilise results from a human-subjects experiment to examine the connection between strategic uncertainty and outcomes in games. Our basic game is a Nash demand game where one player has an outside option available. A “chat” treatment allows bargainers to send cheap-talk messages prior to playing the basic game, and in a “contracts” treatment, they can additionally propose and accept binding contracts. We propose that strategic uncertainty comprises at least two facets: “coordination-type”, which is lower in the chat game than in the basic game, and “rationality-type”, which is lower in the contracts game than in the chat game. We find that both types of strategic uncertainty impact bargaining outcomes: moving from the basic game to the chat game, and thence to contracts, improves several aspects of outcomes, such as higher efficiency, less opting out and less under-demanding. Other results include a treatment effect on the types of agreements that are reached.     

Optimal bilateral trade of multiple objects

We study a private-values buyer–seller problem with multiple objects. Valuations are binary and i.i.d. We construct mechanisms that span the set of all Pareto-efficient outcomes. The induced trading rules for objects are linked in a simple way.     

如何推进重庆农村信息化建设

农村信息化建设是社会主义新农村建设的重要内容。重庆作为全国首个城乡统筹信息化试验区,其农村信息化工作相对滞后,其中地域特殊、基础薄弱是制约重庆农村信息化的重要因素。加强基础设施建设、增加资金投入、培养人才是推动重庆农村信息化建设的有效途径。     

Information acquisition in committees

The goal of this paper is to illustrate the significance of information acquisition in mechanism design. We provide a stark example of a mechanism design problem in a collective choice environment with information acquisition. We concentrate on committees that are comprised of agents sharing a common goal and having a joint task. Members of the committee decide whether to acquire costly information or not at the outset and are then asked to report their private information. The designer can choose the size of the committee, as well as the procedure by which it selects the collective choice, i.e., the correspondence between agents' reports and distributions over collective choices. We show that the ex ante optimal device may be ex post inefficient, i.e., lead to suboptimal aggregation of information from a statistical point of view. For particular classes of parameters, we describe the full structure of the optimal mechanisms.     

Menu theorems for bilateral contracting

This paper studies bilateral contracting where multiple principals negotiate contracts with multiple agents independently. It is shown that pure-strategy equilibrium allocations relative to any ad hoc set of feasible mechanisms are supported by pure-strategy perfect Bayesian equilibria relative to the set of menus. This paper also shows that all equilibrium allocations to any ad hoc set of feasible mechanisms are supported by correlated equilibria relative to the set of menus, where a state is a probability distribution function over payoff-relevant variables. Furthermore, all equilibrium allocations relative to the set of menus persist even if principals use more complex mechanisms.