Group Size Effect and Over-Punishment in the Case of Third Party Enforcement of Social Norms

One of the important topics in public choice is how people's free-riding behavior could differ by group size in collective action dilemmas. This paper experimentally studies how the strength of third party punishment in a prisoner's dilemma could differ by the number of third parties in a group. Our data indicate that as the number of third party punishers increases in a group, the average punishment intensity per third party punisher decreases. However, the decrease rate is very mild and therefore the size of total punishment in a group substantially increases with an increase in group size. As a result, third party punishment becomes a sufficient deterrent against a player selecting defection in the prisoner's dilemma when the number of third party punishers is sufficiently large. Nevertheless, when there are too many third party punishers in a group, a defector's expected payoff is far lower than that of a cooperator due to strong aggregate punishment, while some cooperators are even hurt through punishment. Therefore, the group incurs a huge efficiency loss. Such over-punishment results from third party punishers’ conditional punishment behaviors: their punishment intensity is positively correlated with their beliefs on the peers’ punitive actions. Some possible ways to coordinate punishment among peers even when group size is very large, thus enabling the efficiency loss to be mitigated, are also discussed in the paper

Voluntary Disclosure of Information and Cooperation in Simultaneous-Move Economic Interactions

This paper experimentally studies individuals’ voluntary disclosure of past behaviors and its effects in a finitely repeated two-player public goods game. The experiment data found that voluntary information disclosure strengthens cooperation under certain conditions, although a non-negligible fraction of individuals do not disclose information about the past and proceed to behave opportunistically. On closer inspection, the data revealed that the material incentives of disclosure acts differ according to the matching protocol. Specifically, disclosers receive higher payoffs than non-disclosers if the disclosers are assured to be matched with like-minded disclosers; conversely, disclosers are vulnerable to exploitation by others under random matching. These results suggest that mandatory disclosure helps enhance economic efficiency if individuals’ hiding and uncooperative behaviors are liable to precipitate a collapse in the community norms

Promoting Competition or Helping the Less Endowed? Distributional Preferences and Collective Institutional Choices under Intra-Group Inequality

Unequally distributed resources are ubiquitous. The decision of whether to promote competition or equality is often debated in societies and organizations. With heterogeneous endowments, we let subjects collectively choose between a public good that most benefits the less endowed and a lottery contest in which only one individual in a group receives a prize. Unlike standard theoretical predictions, the majority of subjects, including a substantial number of subjects who believe that their expected payoffs are better in the contest, vote for the public good. Our data suggest that people’s collective institutional choices may be driven by inequality-averse concerns. It also suggests that the collective decision to select the option for the public good depends on voting rules

Play it Again: Partner Choice, Reputation Building and Learning from Finitely-Repeated Dilemma Games

Often the fuller the reputational record people's actions generate, the greater their incentive to earn a reputation for cooperation. However, inability to “wipe clean” one's past record might trap some agents who initially underappreciate reputation's value in a cycle of bad behaviour, whereas a clean slate could have been followed by their “reforming” themselves. In a laboratory experiment, we investigate what subjects learn from playing a finitely repeated dilemma game with endogenous, symmetric partner choice. We find that with a high cooperation premium and good information, investment in cooperative reputation grows following exogenous restarts, although earlier end-game behaviours are observed

In Broad Daylight: Fuller Information and Higher-Order Punishment Opportunities Can Promote Cooperation

The expectation that non-cooperators will be punished can help to sustain cooperation, but there are competing claims about whether opportunities to engage in higher-order punishment (punishing punishment or failure to punish) help or undermine cooperation in social dilemmas. Varying treatments of a voluntary contributions experiment, we find that availability of higher-order punishment opportunities increases cooperation and efficiency when subjects have full information on the pattern of punishing and its history, when any subject can punish any other, and when the numbers of punishment and of contribution stages are not too unequal

State or nature? Endogenous formal versus informal sanctions in the voluntary provision of public goods

We investigate the endogenous formation of sanctioning institutions supposed to improve efficiency in the voluntary provision of public goods. Our paper parallels Markussen et al. (Rev Econ Stud 81:301–324, 2014) in that our experimental subjects vote over formal versus informal sanctions, but it goes beyond that paper by endogenizing the formal sanction scheme. We find that self-determined formal sanctions schemes are popular and efficient when they carry no up-front cost, but as in Markussen et al. informal sanctions are more popular and efficient than formal sanctions when adopting the latter entails such a cost. Practice improves the performance of sanction schemes: they become more targeted and deterrent with learning. Voters’ characteristics, including their tendency to engage in perverse informal sanctioning, help to predict individual voting

"A Free thenar flap – A case report"

We present a case report of a free thenar flap surgery done for a volar right hand middle finger, distal and middle phalanx degloving injury. A free thenar flap is a fasciocutaneous sensate flap supplied by a constant branch of the superficial radial artery and its variable nerve supply. It has a distinct advantage of low donor site morbidity, better cosmesis and texture of the flap. No immobilization is required postop. The donor site can be closed primiarily