Collective Punishment and Self Governance in Public Good Provision

Last registered on April 14, 2026

Pre-Trial

Trial Information

General Information

Title
Collective Punishment and Self Governance in Public Good Provision
RCT ID
AEARCTR-0018347
Initial registration date
April 11, 2026

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
April 14, 2026, 9:10 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

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Primary Investigator

Affiliation
Lingnan University

Other Primary Investigator(s)

PI Affiliation
Macau University of Science and Technology

Additional Trial Information

Status
In development
Start date
2026-06-01
End date
2027-04-20
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
A substantial body of experimental research highlights the importance of penalizing free riders to sustain cooperation. However, subsequent experiments allowing for counter-punishment reveal that most free riders retaliate against their punishers, discouraging altruistic punishment and reducing the penalties for free riders over time. Some experimental economists, such as Nikiforakis (2008), argue that these findings cast doubt on Elinor Ostrom’s Nobel Prize-winning work on self-governance in common resource management. This project explores the ongoing debate on the effectiveness of self-governance by investigating a “collective punishment” mechanism, inspired by Ostrom (1990), to enhance cooperation through both theoretical and empirical approaches.

Our theoretical analysis develops a model where members of a community or group contribute their resources to a public good, guided by two social norms. Initially, the norm of contributing to the public good incentivizes higher contributions. Subsequently, the norm of penalizing those who stray from cooperation leads some individuals to embrace the role of “altruistic punishers.” We aim to investigate how collective punishment can engender a greater number of “altruistic punishers,” especially in the face of potential counter-punishment from non-cooperating members. Our objective is to scrutinize the principles underpinning “collective punishment” within the self-governance of a group or community, focusing on the hierarchical relationship between these two social norms. Subsequently, we will analyze the subgame perfect equilibrium of this mechanism design.

Regarding the empirical aspect, we plan to conduct laboratory experiments to test our theoretical conjectures. Participants will be randomly assigned to one of four treatments: (1) a control treatment featuring a standard public goods game, (2) an individual punishment treatment, (3) a collective punishment treatment without communication, and (4) a collective punishment treatment with communication.

It is crucial to emphasize that in “collective punishment,” the act of punishment is individually chosen and voluntarily executed, serving as a mechanism of self-governance. In this framework, the absence of an external authority to enforce penalties highlights the importance of credibility in determining the suggested donation amounts and levels of punishment within the mechanism design. Based on our theoretical analysis, we hypothesize that Group (4) will exhibit the highest level of cooperation. Additionally, we will investigate whether participants in Groups (3) and (4) can select donation and punishment amounts that are credible for individual implementation, as predicted by our theoretical analysis.
External Link(s)

Registration Citation

Citation
Fan, Simon and Yu Pang. 2026. "Collective Punishment and Self Governance in Public Good Provision." AEA RCT Registry. April 14. https://doi.org/10.1257/rct.18347-1.0
Experimental Details

Interventions

Intervention(s)
The experiment is based on the voluntary contributions mechanism (VCM) game, which is widely used in the literature (Charness and Kuhn 2011). In this game of public good provision, the payoff to each member of a group, i, is as follows:
-e_i+θ (∑_1^N▒e_i )/N (12)
where  is her total endowment, and e_i is her contribution to the public good. Concerning the correlation between theory and empirical results, it is crucial to recognize that earnings in laboratory experiments act as a substitute for "utility" in the theoretical framework.Note that Equation (6) is consistent with our theoretical model above in which u(x)=x and v(x)=θx. It is assumed that θ >1/N, which implies that the socially optimal outcome is e_i=. However, if an individual is entirely selfish, he/she will choose e_i=0 when N is large enough.

The participants in our experiment will be randomly assigned to one of the following four treatment groups:
The basic control treatment, in which the subjects will be asked to make their free choices of donating to the public good.
The individual punishment treatment: Participants in this group will have the option to impose monetary punishments on other group members. They can also seek revenge or counter-punishment after being punished.
The collective punishment treatment (without communications): In this group, participants will vote on several aspects, including the desired level of initial donation, the specific members to be punished based on their actual donations, and the monetary punishment to be imposed on free riders. Participants who are punished will have the opportunity for revenge.
The collective punishment treatment (with communications): In addition to the features in Group 3, participants in this group will be allowed to communicate with each other.

In all experimental groups, there is a two minutes’ deliberation on the proper donation amount to the public good. This discussion aims to ensure a consistent donation norm across all groups, with differences primarily arising from the methods of punishment rather than donation norms themselves. At the end of the discussion, there will be a voting on this amount, and the average of the voting outcome will be informed to all group members. Kessler and Leider (2012) and Krupka, Leider, Jiang (2017) demonstrate the importance of informal agreements in enforcing social norms. However, we hypothesize that the credibility of group members donating based on the average varies among different groups, with the group engaging in collective punishment more likely to conform to the average.

Intervention Start Date
2026-06-20
Intervention End Date
2026-12-31

Primary Outcomes

Primary Outcomes (end points)
In the case of collective punishment, it incorporates certain aspects of “democratic punishment” in a public good game (Ambrus and Greiner, 2019), where a majority vote from group members is required to punish another member. In other words, we will initially follow a similar procedure to that of “democratic punishment” as outlined in Ambrus and Greiner (2019) when designing the treatment for “collective punishment.” However, unlike “democratic punishment,” the extent of punishment in our experiment is entirely determined by the individual choices of each member within the majority group. Additionally, the concept of counter-punishment is not considered in the existing literature on “democratic punishment,” but we do account for the possibility of counter-punishment in Treatments 3 and 4 of our experiment. Therefore, in this study, all punishments are based on the principles of self-governance.
It is important to highlight that in “collective punishment,” the act of punishment is carried out individually. The collective aspect of “collective punishment” lies in the fact that all contributors to the donations engage in a collective discussion, through voting or discussions, to determine the specific members who are to be punished based on their actual donations. Additionally, they decide on the targeted level of monetary punishment that each punisher is expected to impose on free riders. In essence, “collective punishment” differs from “individual punishment” primarily in the presence of a collective voting and/or communication process prior to individual punitive actions. This coordination among potential punishers allows for better alignment and decision-making.
Individual punishment faces challenges in sustaining cooperation due to two reasons. Firstly, an individual punisher must personally bear the cost of punishment, leading to their designation as “altruistic punishers” in the literature (Bowles and Gintis, 2011). Secondly, an individual punisher runs the risk of retaliation. In contrast, collective punishment has the potential to address both of these weaknesses. In collective punishment, each punisher within the coalition faces a relatively low risk of retaliation, and there is an expectation of contribution to the punishment from everyone in the majority group. Consequently, we anticipate that Treatment 4 will result in the highest level of cooperation, followed by Treatment 3.
We plan to conduct our laboratory experiments by enlisting university students, a widely adopted approach in academic research. The participants for our experimental study will be recruited through university bulletin board systems and online posters. To ensure appropriate subject pool recruitment procedures, we will closely adhere to the guidelines outlined by Greiner (2015). All experiment sessions will be computerized using the z-Tree software package (Fischbacher, 2007).
In our experiment, each participant engages in 20 periods. At the start of each period, participants receive a fixed amount of experimental currency units (ECUs), which they can allocate to either private or public goods. Each period consists of multiple stages. The initial stage is the contribution stage where participants decide how much to contribute to the public good. Participants’ contributions to the public good are revealed to others after the donation stage. Subsequently, there are punishment stages where participants can administer punishments and counter-punishments.
All individual punishments are implemented in the form of reducing other players’ earnings while simultaneously reducing the punisher’s own earnings. In the case of collective punishment treatments, participants first observe the donations made by all players. A voting or discussion process then takes place to determine the “free riders” who will be subject to punishment. Subsequently, cooperators engage in discussions to establish the appropriate level of punishment before each member of the cooperative majority group carries out the punishments. If no player assigns a punishment during a given stage, the period concludes, and a new one begins.
Group size often plays a crucial role in interpersonal interactions (Lim, Matros, and Turocy, 2014), and it can significantly impact the effectiveness of collective punishment for various reasons. On one hand, in larger groups, the individual who contributes the least to the public good may feel more isolated and could potentially face more substantial collective punishment. Consequently, cooperation may increase within larger groups when the mechanism of collective punishment is implemented. On the other hand, as the group size expands, individuals may feel less connected to the community (Ellickson, 2001). Hence, the overall impact of increasing group size is theoretically ambiguous but could have notable empirical significance. To examine this effect, we will introduce variations in group size during our experiments. Specifically, we will have two group sizes: 4 and 8 participants, respectively.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The participants in our experiment will be randomly assigned to one of the following four treatment groups:
1. The basic control treatment, in which the subjects will be asked to make their free choices of donating to the public good.
2. The individual punishment treatment: Participants in this group will have the option to impose monetary punishments on other group members. They can also seek revenge or counter-punishment after being punished.
3. The collective punishment treatment (without communications): In this group, participants will vote on several aspects, including the desired level of initial donation, the specific members to be punished based on their actual donations, and the monetary punishment to be imposed on free riders. Participants who are punished will have the opportunity for revenge.
4. The collective punishment treatment (with communications): In addition to the features in Group 3, participants in this group will be allowed to communicate with each other.

Three critical points should be highlighted. Firstly, in all experimental groups, there is a two minutes’ deliberation on the proper donation amount to the public good. This discussion aims to ensure a consistent donation norm across all groups, with differences primarily arising from the methods of punishment rather than donation norms themselves. At the end of the discussion, there will be a voting on this amount, and the average of the voting outcome will be informed to all group members. Kessler and Leider (2012) and Krupka, Leider, Jiang (2017) demonstrate the importance of informal agreements in enforcing social norms. However, we hypothesize that the credibility of group members donating based on the average varies among different groups, with the group engaging in collective punishment more likely to conform to the average.
Secondly, for the sake of experiment simplification, in our benchmark experiments described above we solely implement monetary penalties for free-riders in donations Nevertheless, we will integrate both non-monetary and monetary punishments in the extension of experiments later on.
Thirdly, the introduction of Treatment 4 underscores the significance of communication in collaborative settings, drawing inspiration from case studies in Ostrom (1990) and various experimental research endeavors (Levy, Padgitt, Peart, Houser, and Xiao 2011, Feltovich and Grossman 2015, Bartling, Valero, Weber, and Yao, forthcoming). As an illustration, Bartling, Valero, Weber, and Yao (forthcoming) conducted an experiment that featured an 8-minute interval allowing participants to communicate via an electronic chat window. They guided discussions on public discourse by encouraging participants to deliberate on the social acceptability or unacceptability of trading a product that negatively impacts third parties. Furthermore, participants were prompted to examine how trading this product aligns with or deviates from widely held norms regarding appropriate, ethical, and moral conduct. Participants were encouraged to freely express their opinions while refraining from personally identifying, obscene, or disparaging comments. The study revealed that such public discourse notably fosters socially responsible market behaviors. In our study, Treatments 3 and 4 diverge in terms of communication: Treatment 4 permits communication, while Treatment 3 does not. Similar to Bartling, Valero, Weber, and Yao (forthcoming), in Treatment 4 we will allow group members to communicate via an electronic chat window for 5 minutes before they take the possible actions against free riders. We hypothesize that Treatment 4 represents a more advanced approach to collective punishment compared to Treatment 3. Communication in Treatment 4 will occur prior to the implementation of punishments.
Experimental Design Details
Not available
Randomization Method
randomization done in office by a computer
Randomization Unit
individual
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
600 university students
Sample size: planned number of observations
600 university students
Sample size (or number of clusters) by treatment arms
2000
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Lingnan University
IRB Approval Date
2025-02-02
IRB Approval Number
13502225