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.     

Playing the trust game with other people’s money

We experimentally investigate to what extent people trust and honor trust when they are playing with other people’s money (OPM). We adopt the well-known trust game by Berg et al. (in Games Econ. Behav. 10:122–142, 1995), with the difference that the trustor (sender) who sends money to the trustee (receiver) does this on behalf of a third party. We find that senders who make decisions on behalf of others do not behave significantly different from senders in our baseline trust game who manage their own money. But receivers return significantly less money when senders send a third party’s money. As a result, trust is only profitable in the baseline trust game, but not in the OPM treatment. The treatment effect among the receivers is gender specific. Women return significantly less money in OPM than in baseline, while there is no such treatment effect among men. Moreover, women return significantly less than men in the OPM treatment.     

Truth,Trust, and Sanctions: On Institutional Selection in Sender–Receiver Games*

We have conducted a laboratory experiment to investigate the impact of institutions and institutional choice on truth‐telling and trust in sender–receiver games. We find that in an institution with sanctioning opportunities, receivers sanction predominantly after having trusted lies. Individuals who sanction are responsible for truth‐telling beyond standard equilibrium predictions, and they are more likely to choose the sanctioning institution. Sanctioning and non‐sanctioning institutions coexist if their choice is endogenous, and the former shows a higher level of truth‐telling but lower material payoffs. Our experimental findings are consistent with logit agent quantal response equilibrium with two distinct groups of individuals: one consisting of subjects who experience non‐monetary lying costs as senders and non‐monetary costs when being lied to as receivers, and the other consisting of payoff maximizers.     

Decentralized advice

We compare the amount of information credibly transmitted by cheap talk when information is centralized to one sender and when it is decentralized, with each of several senders holding a distinct but interdependent piece. Under centralization, full information transmission is typically impossible. Under decentralization, however, the number of receivers is decisive: decentralized communication with one receiver is completely uninformative, but decentralized communication with multiple receivers can be fully informative. We analyze the extent of such fully-informative communication, and apply our results to the issue of transparency in advisory committees.     

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.     

Expressed preferences and behavior in experimental games

Participants in experimental games typically can only choose actions, without making comments about other participants' future actions. In sequential two-person games, we allow first movers to express a preference between responder choices. We find that responder behavior differs substantially according to whether first movers express a hope for favorable or unfavorable treatment. Responders largely ignore first movers' expressed preferences for favorable responses, however, when the first movers misbehave. As in earlier experiments without preference expression, subjects assign a high positive weight to another person's payoffs when ahead and misbehavior elicits a strong negative response. Logit regressions estimate the weight placed on another (non-misbehaving) person's payoffs to be positive, even when one is behind. There is suggestive evidence that positive reciprocity is enhanced when a preference for favorable treatment is expressed.     

Measuring agents’ reaction to private and public information in games with strategic complementarities

In games with strategic complementarities, public information about the state of the world has a larger impact on equilibrium actions than private information of the same precision, because public signals are more informative about the likely behavior of others. We present an experiment in which agents’ optimal actions are a weighted average of the fundamental state and their expectations of other agents’ actions. We measure the responses to public and private signals. We find that, on average, subjects put a larger weight on the public signal. In line with theoretical predictions, as the relative weight of the coordination component in a player’s utility increases, players put more weight on the public signal when making their choices. However, the weight is smaller than in equilibrium, which indicates that subjects underestimate the information contained in public signals about other players’ beliefs.     

Buyer-Option Contracts Restored: Renegotiation, Inefficient Threats, and the Hold-Up Problem

"Buyer-option" contracts, in which the buyer selects the productvariant to be traded and chooses whether to accept delivery,are often used to solve holdup problems. We present a simplegame that focuses sharply on subgames in which the buyer proposesinefficient actions in order to improve his bargaining position.We argue for one of several alternative ways to model this situation.We then apply that modeling choice to recent models of the foundationsof incomplete contracts and show that a buyer-option contractis sufficient to induce first-best outcomes.     

Efficiency of continuous double auctions under individual evolutionary learning with full or limited information

In this paper we explore how specific aspects of market transparency and agents’ behavior affect the efficiency of the market outcome. In particular, we are interested whether learning behavior with and without information about actions of other participants improves market efficiency. We consider a simple market for a homogeneous good populated by buyers and sellers. The valuations of the buyers and the costs of the sellers are given exogenously. Agents are involved in consecutive trading sessions, which are organized as a continuous double auction with order book. Using Individual Evolutionary Learning agents submit price bids and offers, trying to learn the most profitable strategy by looking at their realized and counterfactual or “foregone” payoffs. We find that learning outcomes heavily depend on information treatments. Under full information about actions of others, agents’ orders tend to be similar, while under limited information agents tend to submit their valuations/costs. This behavioral outcome results in higher price volatility for the latter treatment. We also find that learning improves allocative efficiency when compared to outcomes with Zero-Intelligent traders.     

Exploiting moral wiggle room: experiments demonstrating an illusory preference for fairness

This paper explores whether generosity in experiments is truly evidence of concern for desirable social outcomes. We conduct an experiment using a binary version of the dictator game. We introduce several treatments in which subjects are able to leave the relationship between their actions and resulting outcomes uncertain, either to themselves or to another subject influenced by those actions, thus giving subjects the moral “wiggle room” to behave self-interestedly. We find significantly less generous behavior in these manipulations, relative to a baseline in which the relationship between actions and outcomes is transparent. We conclude that many subjects behave fairly in the baseline case mainly because they intrinsically dislike appearing unfair, either to themselves or others. We thank Cristina Bicchieri; Iris Bohnet; Colin Camerer; Robyn Dawes; Ernst Fehr; George Loewenstein; John Patty; Charlie Plott; Matthew Rabin; seminar participants at Carnegie Mellon, Berkeley, Cornell, Emory, and Princeton; participants at the 2003 Public Choice, 2003 ESA, 2003 SJDM, and 2004 BDRM meetings; and anonymous referees for helpful comments and suggestions. We greatly appreciate the access to resources at the Pittsburgh Experimental Economics Laboratory (PEEL) at the University of Pittsburgh. This research was funded by a Carnegie Mellon Berkman Faculty Development Grant to Weber and a Russell Sage Behavioral Economics Small Grant to Dana.     

Speculative dynamics

We develop a method for solving for equilibrium outcomes in stationary strategic settings in which speculators are informationally large and understand how their actions affect the information content of prices. This allows us to characterize speculation by institutional investors who receive private long-lived information on a recurring basis, and trade strategically. When the underlying asset value process has a stationary autoregressive structure, we develop a contraction mapping argument to solve for the stationary linear equilibrium. We derive analytically and numerically how the characteristics of private information—its quantity, persistence and correlation, and division among speculators—affect trading profits, pricing and trading strategies. Our central finding is that what matters for equilibrium outcomes are the most recent signals that speculators receive. Speculators trade so much more aggressively on new information than old that the bulk of their profits come from their two or three most recent private signals. Trading on past prices drops off faster yet; effectively only the most recent price matters.     

The victim matters – experimental evidence on lying,moral costs and moral cleansing

In an experiment on moral cleansing with an endogenously manipulated moral self-image, we examine the role of the addressee of an immoral action. We find that cheating is highest and moral cleansing lowest when subjects cheat at the expense of the experimenter, while cheating is lowest and moral cleansing highest once cheating harms another participant. A subsequent measurement of subjects’ moral self-image supports our interpretation that the occurrence of moral cleansing crucially depends on the moral costs resulting from immoral actions directed at individuals in different roles. Our results can help to explain the different propensity to cheat and conduct moral cleansing when immoral actions harm either another person or representatives of organizations.     

Garbling of signals and outcome equivalence

In a game with incomplete information players receive stochastic signals about the state of nature. The distribution of the signals given the state of nature is determined by the information structure. Different information structures may induce different equilibria.Two information structures are equivalent from the perspective of a modeler, if they induce the same equilibrium outcomes. We characterize the situations in which two information structures are equivalent in terms of natural transformations, called garblings, from one structure to another. We study the notion of ‘being equivalent to’ in relation with three equilibrium concepts: Nash equilibrium, agent normal-form correlated equilibrium and the belief invariant Bayesian solution.     

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.     

Empirical Implications of Equilibrium Bidding in First-Price, Symmetric, Common Value Auctions

This paper studies federal auctions for wildcat leases on the Outer Continental Shelf from 1954 to 1970. These are leases where bidders privately acquire (at some cost) noisy, but equally informative, signals about the amount of oil and gas that may be present. We develop tests of rational and equilibrium bidding in a common values model that are implemented using data on bids and ex post values. We also use data on tract location and ex post values to test the comparative static prediction that bidders may bid less aggressively in common value auctions when they expect more competition. We find that bidders are aware of the "winner's curse" and their bidding is largely consistent with equilibrium.     

Learning from private information in noisy repeated games

We study the perfect type-contingently public ex-post equilibrium (PTXE) of repeated games where players observe imperfect public signals of the actions played, and both the payoff functions and the map from actions to signal distributions depend on an unknown state. The PTXE payoffs when players are patient are determined by the solutions to a family of linear programming problems. Using this characterization, we develop conditions under which play can be as if the players have learned the state. We provide a sufficient condition for the folk theorem, and a characterization of the PTXE payoffs in games with a known monitoring structure.     

Credulity, lies, and costly talk

This paper studies a model of strategic communication by an informed and upwardly biased sender to one or more receivers. Applications include situations in which (i) it is costly for the sender to misrepresent information, due to legal, technological, or moral constraints, or (ii) receivers may be credulous and blindly believe the sender's recommendation. In contrast to the predictions obtained in the benchmark cheap talk model, our model admits a fully separating equilibrium, provided that the state space is unbounded above. The language used in equilibrium is inflated and naive receivers are deceived.     

Network architecture, salience and coordination

This paper reports the results of an experimental investigation of dynamic games in networks. In each period, the subjects simultaneously choose whether or not to make an irreversible contribution to the provision of an indivisible public good. Subjects observe the past actions of other subjects if and only if they are connected by the network. Networks may be incomplete so subjects are asymmetrically informed about the actions of other subjects in the same network, which is typically an obstacle to the attainment of an efficient outcome. For all networks, the game has a large set of (possibly inefficient) equilibrium outcomes. Nonetheless, the network architecture makes certain strategies salient and this in turn facilitates coordination on efficient outcomes. In particular, asymmetries in the network architecture encourage two salient behaviors, strategic delay and strategic commitment. By contrast, we find that symmetries in the network architecture can lead to mis-coordination and inefficient outcomes.     

Winner's curse without overbidding

We report the results of a series of second-price auction experiments where each bidder's signal is given by a normally distributed value plus a normally distributed error. While bidders’ values differ in one treatment they are the same in another, which allows for a direct test of the “winner's curse” irrespective of confounding factors. Bidders may also fall prey to a “news curse” when they do not sufficiently take into account that signals and errors are correlated. We find that the effects of the winner's curse are mitigated by a news curse and loss or risk aversion.     

Signaling and mediation in games with common interests

Players who have a common interest are engaged in a game with incomplete information. Before playing they get differential stochastic signals that depend on the actual state of nature. These signals provide the players with partial information about the state of nature and may also serve as a means of correlation.Different information structures induce different outcomes. An information structure is better than another, with respect to a certain solution concept, if the highest solution payoff it induces is at least that induced by the other structure. This paper characterizes the situation where one information structure is better than another with respect to various solution concepts: Nash equilibrium, strategic-normal-form correlated equilibrium, agent-normal-form correlated equilibrium and belief-invariant Bayesian solution. These solution concepts differ from one another in the scope of communication allowed between the players. The characterizations use maps that stochastically translate signals of one structure to signals of another.