Belief in Mean Reversion and the Disposition Effect: An Experimental Test

The disposition effect refers to investors' tendency to disproportionately sell more winning than losing assets. The literature mostly offered indirect evidence regarding its cause. Using a lab experiment, the author directly evaluates the two competing behavioral mechanisms for this effect: belief in mean reversion and dual risk attitudes of prospect theory. The participants were endowed with some hypothetical assets, observed price charts, and made selling decisions. Sixty-one percent of them exhibited significant disposition effect. The author elicited the participants' risk attitude parameters and beliefs about price movements, and found that beliefs, especially those in the loss domain, but not the dual risk attitudes, significantly contributed to the between-subject variation of the disposition effect. The results from a goodness-of-fit test also favor the belief mechanism.     

Bounded Rationality in Principal‐Agent Relationships

We conducted six treatments of a standard moral hazard experiment with hidden action. The behavior in all treatments and periods was inconsistent with established agency theory. In the early periods, behavior differed significantly between treatments. This difference largely vanished in the final periods. We used logit agent quantal response equilibrium (LAQRE) as a device to grasp boundedly rational behavior and found the following: (1) LAQRE predictions are much closer to subjects' behavior in the laboratory; (2) LAQRE probabilities and experimental behavior show remarkably similar patterns; and (3) including social preferences in LAQRE does not better explain the experimental data; (4) LAQRE cannot explain the contract offers of some players who seem to choose some focal contract parameters.     

Impulse balance in the newsvendor game

One striking behavioral phenomenon is the “pull-to-center” bias in the newsvendor game: facing stochastic demand, subjects tend to order quantities between the expected profit maximizing quantity and mean demand. We show that the impulse balance equilibrium, which is based on a simple ex-post rationality principle along with an equilibrium condition, predicts the pull-to-center bias and other, more subtle observations in the laboratory newsvendor game.     

Multiple switching behaviour in different display formats of multiple price lists

A common approach to elicit risk attitude is the multiple price list with a series of binary choices. However, a frequently observed problem when using multiple price lists is that participants switch more than once from the safer to the riskier option, thus exhibiting multiple switching behaviour. The present study analyses whether the visualization of different multiple price lists reduce multiple switching behaviour. Therefore, we conduct two types of multiple price lists in two different display formats. Participants are randomly assigned into a textual or a visual group and carry out both multiple price lists in the corresponding display format. Our results reveal that different types of multiple price lists lead to differences in the extent of multiple switching behaviour. Moreover, we show that the visualization of a multiple price list can be an instrument to greatly reduce multiple switching behaviour.     

Group polarization in the team dictator game reconsidered

While most papers on team decision-making find that teams behave more selfishly, less trustingly and less altruistically than individuals, Cason and Mui (1997) report that teams are more altruistic than individuals in a dictator game. Using a within-subjects design we re-examine group polarization by letting subjects make individual as well as team decisions in an experimental dictator game. In our experiment teams are more selfish than individuals, and the most selfish team member has the strongest influence on team decisions. Various explanations for the different findings in Cason and Mui (1997) and in our paper are discussed.      

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.     

Purely procedural preferences - Beyond procedural equity and reciprocity

We conduct experiments in which parties face a pair of two-player pie-splitting procedures. Parties submit their strategy in each, their beliefs about their opponent's choices, and are also asked whether they prefer one procedure over the other. The procedures – a yes-no game, an ultimatum game, and a dictator game – are designed such that by all existing economic preference models, whether distributive or procedural, parties should be indifferent between them. In particular, the procedures should yield the same outcomes, the same expected outcomes and carry the same information on parties' intentions. At the same time, the procedures differ in the way they distribute decision and information rights across players, and also in their complexity and efficiency. Experimentally, parties do indeed still reveal preferences over the procedures at hand. To explore why this happens, we elicit individuals' simplicity and efficiency ratings of the procedures, and also the degree by which individuals invoke the equality of basic rights and liberties in their moral judgement – an ethical criterion not yet captured by any preference model. The preferences we find link to this data. We explore formalizations for such preferences.     

How do judgmental overconfidence and overoptimism shape innovative activity?

Recent field evidence suggests a positive link between overconfidence and innovative activities. In this paper we argue that the connection between overconfidence and innovation is more complex than the previous literature suggests. In particular, we show theoretically and experimentally that different forms of overconfidence may have opposing effects on innovative activity. While overoptimism is positively associated with innovation, judgmental overconfidence is negatively linked to innovation. Our results indicate that future research is well advised to take into account that the relationship between innovation and overconfidence may crucially depend on what type of overconfidence is most prevalent in a particular context.     

Incentives and group identity

This paper investigates in a principal–agent environment whether and how group membership influences the effectiveness of incentives and when incentives can have “hidden costs”, i.e., a detrimental effect. We show experimentally that in all interactions control mechanisms can have hidden costs for reasons specific to group membership. In within-group interactions control has detrimental effects because the agent does not expect to be controlled and reacts negatively when being controlled. In between-group interactions, agents perceive control more hostile once we condition on their beliefs about principals' behavior. Our finding contributes to the micro-foundation of psychological effects of incentives.