Costly Renegotiation in Repeated Bertrand Games

This paper extends the concept of weak renegotiation-proof equilibrium (WRP) to allow for costly renegotiation and shows that even small renegotiation costs can have dramatic effects on the set of equilibria. More specifically, the paper analyzes the infinitely repeated Bertrand game. It is shown that for every level of renegotiation cost there exists a discount factor such that any collusive profit can be supported as an equilibrium outcome. Hence, any arbitrary small renegotiation cost will suffice to facilitate collusive outcomes for sufficiently patient firms. This result stands in stark contrast to the unique pure-strategy WRP equilibrium without renegotiation costs, which implies marginal-cost pricing in every period. Moreover, in comparison to the findings of McCutcheon (1997), who states that renegotiation costs have to be substantial to facilitate collusion, this result points to a quite different conclusion.Noncooperative game theory; Weak Renegotiation-proofness; Costly Renegotation; Repeated Bertrand games

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. Pre-play communication only has a significant impact on cooperation when no intra-play communication is possible. The results suggest that the credibility of pre-play messages may depend crucially on future communication opportunities.Communication; Cooperation; Renegotiation; Experiments

Price competition, level-k theory and communication

This paper analyzes communication in a price competition game using the level-$k$ theory of bounded rationality. The level-k analysis predicts prices to be higher with communication than without. Our experimental evidence lends support to the view that communication affects subjects in a way that is compatible with the level-k model, indicating that people lie in order to fool other players that they believe do less thinking. Moreover, the results indicate that the predictive power of the level-k model does crucially depend on the possibility for high level players to form homogenous beliefs about the behavior of the level-0 player

Selection and Mode Effects in Risk Preference Elicitation Experiments

We combine data from a risk preference elicitation experiment conducted on a representative sample via the Internet with laboratory data on students for the same experiment to investigate effects of implementation mode and of subject pool selection. We find that the frequency of errors in the lab experiment is drastically below that of the representative sample in the Internet experiment, and average risk aversion is also lower. Considering the student-like subsample of the Internet subjects and comparing a traditional lab design with an Internet-like design in the lab gives two ways to decompose these differences into differences due to subject pool selection and differences due to implementation mode. Both lead to the conclusion that the differences are due to selection and not implementation mode. An analysis of the various steps leading to participation or non-participation in the Internet survey leads shows that these processes are selective in selecting subjects who make fewer errors, but do not lead to biased conclusions on risk preferences. These findings point at the usefulness of the Internet survey as an alternative to a student pool in the laboratory if the ambition is to use the experiments to draw inference on a broad population.risk aversion, internet surveys, laboratory experiments

Self-Scanning and Self-Control: A Field Experiment on Real-Time Feedback and Shopping Behavior

Payment and checkout at retail stores is increasingly being replaced by automated systems. One recent technological invention in this area is mobile self-scanning in which customers carry a mobile scanner while shopping. Mobile self-scanners give real-time feedback on spending. The device increases price saliency and enables customers to keep track of the total amount spent. Using a field experiment, we test if mobile self-scanning affects shopping behavior. Consumers of two grocery stores were allocated randomly to use a mobile self-scanner or not. Overall, we find that using the self-scanner has a negative but insignificant effect on total amount spent. However, the response to using the scanner is heterogeneous and for customers with low self-control, it significantly reduces both their spending and number of items bought when using the mobile scanner. Moreover, we find that consumers with low self-control are more likely to use the self-scanner than individuals with high self-control. Taken together, our results suggest that sophisticated individuals, that is, individuals who are aware of their self-control problem, use the scanner to control their spending

Income and Ideology:How Personality Traits, Cognitive Abilities, and Education Shape Political Attitudes

1Support for this research from the Carlsberg Foundation is gratefully acknowledged. We thank Ke