Ben Greiner

Engineering Trust: Reciprocity in the Production of Reputation Information

Reciprocity in feedback giving distorts the production and content of reputation information in a market, hampering trust and trade efficiency. Guided by feedback patterns observed on eBay and other platforms, we run laboratory experiments to investigate how reciprocity can be managed by changes in the way feedback information flows through the system, leading to more accurate reputation information, more trust, and more efficient trade. We discuss the implications for theory building and for managing the redesign of market trust systems. This paper was accepted by Teck Ho, decision analysis.

How Individual Preferences are Aggregated in Groups: An Experimental Study

This paper experimentally investigates how individual preferences, through unrestricted deliberation, get aggregated into a group decision in two contexts: reciprocating gifts, and choosing between lotteries. In both contexts we find that median group members have a significant impact on the group decision, but particular other members also have some influence. Non-median members closer to the median tend to have more influence than other members. By investigating the same individual’s influence in different groups, we find evidence for relative position in the group having a direct effect on influence. We do not find evidence that group choice exhibits a shift in a particular direction that is independent of member preferences and caused by the group decision context itself. We also find that group deliberation not only involves bargaining and compromise, but it also involves persuasion: preferences tend to shift towards the choice of the individual’s previous group, especially for those with extreme individual preferences.

Democratic Punishment in Public Good Games with Perfect and Imperfect Observability

In the context of repeated public good contribution games, we experimentally investigate the impact of democratic punishment, when members of a group decide by majority voting whether to inflict punishment on another member, relative to individual peer-to-peer punishment. Democratic punishment leads to more cooperation and higher average payoffs, both under perfect and imperfect monitoring of contributions, primarily by curbing anti-social punishment and thereby establishing a closer connection between a member’s contribution decision and whether subsequently being punished by others. We also find that participating in a democratic punishment procedure makes even non-contributors’ punishment intentions more pro-social.

New Experimental Results on the Solidarity Game

This paper revisits and extends the experiment on the solidarity game by Selten and Ockenfels (1998). We replicate the basic design of the solidarity game and extend it in order to t test the robustness of the ‘fixed total sacrifice’ effect and the applied strategy method. Our results only partially confirm the validity of the fixed total sacrifice effect. In a treatment with constant group-endowment rather than constant winner-endowment the predominance of the ‘fixed total sacrifice’ behavior is replaced by ‘fixed relative gift’ behavior. We additionally introduce a measure of personality characteristics and compare its specific components with pro-social gift behavior in our experiments. We don’t find correlations between actual gift behavior and measures of empathy-driven pro-social behavior used in social science.

Auction Format and Auction Sequence in Multi-Item Multi-Unit Auctions -- An Experimental Study

We experimentally study the effect of auction format (sealed-bid vs. closed clock vs. open clock) and auction sequence (simultaneous vs. sequential) on bidding behaviour and auction outcomes in auctions of multiple related multi-unit items. Prominent field applications are the sale of emission permits, fishing rights, and electricity. We find that, when auctioning simultaneously, clock auctions outperform sealed-bid auctions in terms of efficiency and revenues. This advantage disappears when the items are auctioned sequentially. In addition, auctioning sequentially has positive effects on total revenues across all auction formats, resulting from fiercer competition on the item auctioned first.

Dispute Resolution or Escalation? The Strategic Gaming of Feedback Withdrawal Options in Online Markets

Many online markets encourage traders to make good after an unsatisfactory transaction by offering the opportunity to withdraw negative reputational feedback in a dispute resolution phase. Motivated by field evidence and guided by theoretical considerations, we use laboratory markets with two-sided moral hazard to show that this option, contrary to the intended purpose, produces an escalation of dispute. The mutual feedback withdrawal option creates an incentive to leave negative feedback, independent of the opponent’s behavior, to improve one’s bargaining position in the dispute resolution phase. This leads to distorted reputation information and less trust and trustworthiness in the trading phase. Buyers who refuse to give feedback strategically, even when it comes at a personal cost, mitigate the detrimental impact. It is also mitigated in markets with one-sided moral hazard and a unilateral feedback withdrawal option. The supplementary appendix is available at https://doi.org/10.1287/mnsc.2017.2802. T...

Separation of prescription and treatment in health care markets: A laboratory experiment: Separation of Prescription and Treatment - A Laboratory Experiment

Health care is a credence good, and its market is plagued by asymmetric information. In this paper, we use a laboratory experiment to test the performance of a potential remedy discussed in the applied literature, the separation of prescription and treatment activities. We observe a significant amount of overtreatment (and a smaller nonpredicted amount of undertreatment) in our baseline environment. Requiring a different than the treating physician to provide diagnosis and prescription for free is an effective way to reduce overtreatment in our laboratory setting. This effect, however, is partially offset by an increased frequency of undertreatment. Allowing prescription and treatment physicians to independently set prices for their services reduces efficiency due to coordination failures: In sum, prices are often higher than expected benefit of patients, who in turn do not attend to the physician. Also contrary to theory, bargaining power does not play a significant role for the distribution of profits between physicians.

Conflict Resolution vs. Conflict Escalation in Online Markets

Many online markets encourage traders to make good after an unsatisfactory transaction by offering the opportunity of withdrawing negative reputational feedback in a conflict resolution phase. Motivated by field evidence and guided by theoretical considerations, we use laboratory markets with two-sided moral hazard to show that this option, contrary to the intended purpose, produces an escalation of conflict in the form of strategically distorted reputation information and less trust and trustworthiness in the trading phase. The detrimental impact is mitigated by buyers who refuse to give feedback strategically, even when it comes at a cost to themselves. It is also mitigated in markets with one-sided moral hazard.