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Sustainability as a Dynamic Game

Last registered on November 10, 2022


Trial Information

General Information

Sustainability as a Dynamic Game
Initial registration date
January 18, 2022

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
January 18, 2022, 6:37 PM EST

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

Last updated
November 10, 2022, 2:18 AM EST

Last updated is the most recent time when changes to the trial's registration were published.



Primary Investigator

Université de Fribourg

Other Primary Investigator(s)

PI Affiliation
University of Fribourg
PI Affiliation
PI Affiliation
University of Fribourg

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Sustainability is a crucial concept in the environmental domain, but also in other areas such as financial matters or regarding personal health. Sustainability means using resources in a way that does not compromise the availability of those resources tomorrow. We propose a dynamic threshold public goods game that captures essential features of sustainability. First, the game is dynamic in the sense that the actions played in each period have consequences for future periods. Second, over-using given resources (i.e. above a certain threshold) leads to a decline of these resources. Finally, in many applications, such as the climate and environment preservation, cooperation between many individuals is required to reach a sustainable path, while the temptation to over-use resources is strong. Our game reflects this with its public goods character when there is more than one decision maker. We derive equilibrium behavior and test the predictions in a lab experiment. Our experimental design includes a single versus multi-player game treatment to assess the role of strategic interactions and a high versus low threshold treatment. We want to investigate whether sustainability is achieved more often when it is an equilibrium strategy, and how different personality traits moderate the chosen strategies.
External Link(s)

Registration Citation

Buechel, Berno et al. 2022. "Sustainability as a Dynamic Game." AEA RCT Registry. November 10.
Sponsors & Partners


Experimental Details


We study the sustainability game on the online platform Prolific.

Our experimental design includes three treatments.
T-Baseline: 4-player groups with high threshold
Treatment T-OnePlayer: 1-player "groups" with high threshold
Treatment T-LowThreshold: 4-player groups with low threshold

The baseline treatment represents a pure social dilemma: it is socially optimal for the group to contribute the threshold amount but it is individually rational for each player to defect, i.e. contributing zero. Treatment T-OnePlayer eliminates strategic interactions between players and has a unique equilibrium that coincides with the social optimum.Treatment T-LowThreshold lowers the threshold that must be met to achieve sustainability and has both defection and cooperation (i.e. contributing according to the threshold) as equilibria.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Individual Level: Contribution share, equilibrium play (cooperation or defection)
Group Level: Endowment, threshold met, contribution share
Primary Outcomes (explanation)
Contribution share is the number of points a player contributes to the common account divided by the endowment in the current period.
Equilibrium play is a binary variable that equals 1 if a player's contribution share is approximately equal to a given strategy (either cooperation or defection) and 0 otherwise.
Threshold met is a binary variable that equals 1 if the total number of points contributed by a group equals or exceeds the threshold in a given period.

Secondary Outcomes

Secondary Outcomes (end points)
Individual Level: Gains
Group Level: Sustainability, waste, standard deviation of contributions
Secondary Outcomes (explanation)
Gains in a given period is the number of points a player kept on his private account.
Sustainability is a binary variable that equals 1 if the group has reached the threshold in all preceding periods.
Waste is the amount a group has contributed minus the threshold amount, conditional on having met the threshold.
Standard deviation of contributions is measured within group for each period of the game.

Experimental Design

Experimental Design
The experiment will be run online and include 270 participants randomly assigned to the three treatment groups: T-Baseline, T-OnePlayer, and T-LowThreshold. The experiment lasts about one hour and includes 4 parts:

Part 1: Sustainability game.
Participants read the instruction for the sustainability game and respond to comprehension questionnaire. The computer then forms groups of 4 players (in T-Baseline and T-T-LowThreshold) or 1 player (in T-OnePlayer).
The sustainability game is a dynamic game played over a random number of periods. In each period, players are given a certain number of points as an endowment and must decide how to split these points between a private and a special account. The private account represents individual gains while the special account, which is common for all members of a group, determines future endowments. At the end of the period, players are informed about the contributions of the other members in their group (in T-Baseline and T-LowThreshold), the total contribution of their group, whether the threshold was met or not and their endowment for the next period. In relative terms the stage game is the same in every period.
The whole game is repeated 6 times.

Part 2: Elicitation of risk aversion
Players receive 100 points and must decide how many to invest in a profitable but risky project. We measure risk aversion with the amount invested by each player.

Part 3 Measuring cognitive abilities
We measure cognitive abilities using 12 questions out of the Set 2 of the Raven Advanced Progressive Matrices.

Part 4: Personality, ecological and demographic questionnaires
Personality test: The test uses 24 items from the International Personality Item Pool to measure two aspects of participants’ personality (Agreeableness and Conscientiousness).
New ecological paradigm: 15 items to measure pro-environmental orientation, following Dunlap et al (2000)
CO2 footprint questionnaire: 6 questions based on the WWF Swiss footprint calculator, based on Berger and Wyss (2021)
Demographic questionnaire
Experimental Design Details

Randomization Method
Treatments are randomly assigned to separate sessions. Randomization within the game (number of periods) is done by the computer.
Randomization Unit
Treatment assignment is randomized on the experimental sessions. Number of periods that a game lasts is randomized at group level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
30 groups per treatment, i.e. 90 groups in total.
Group size is four for T-Baseline and T-LowThreshold and one for T-OnePlayer. Number of participans should therefore be 270.
Sample size: planned number of observations
270 participants
Sample size (or number of clusters) by treatment arms
30 groups per treatment.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials


Document Name
Document Type
Document Description

MD5: 1c33a8eb5aad7ef37f3356bfa8eccbc5

SHA1: 6d3d55bef3a2cfdf90e2c9043d827281401d2c8e

Uploaded At: January 17, 2022


Institutional Review Boards (IRBs)

IRB Name
Unidistance ethics committee
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

Analysis plan for Sustainability in a dynamic public goods game

MD5: c0295782c4110e3282b051c55f9b2954

SHA1: f138c2bade403cd7aa0d4649fff1e4a48be1df57

Uploaded At: January 15, 2022


Post Trial Information

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Is the intervention completed?
Intervention Completion Date
January 30, 2022, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
June 29, 2022, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
282 participants (forming 63 groups of four and 30 single players)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
282 participants
Final Sample Size (or Number of Clusters) by Treatment Arms
31 groups of four participants in T-Baseline, 32 groups of four participants in T-LowThreshold, 30 single participants in T-OnePlayer
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Sustainability is a fundamental concept in the environmental domain, but also in other domains, e.g., regarding personal health. Sustainability means using resources today in a way that does not compromise the availability of resources tomorrow. In this paper, we propose and test a model that incorporates the essential features of sustainability, as they are not fully covered in the pre-existing literature. First, our Sustainability Game is dynamic in the sense that the actions played in each period have consequences for future periods. Second, there is a contribution threshold that must be reached in order to maintain the level of resources. The threshold captures that some use of resources can be absorbed, while over-using leads to a decline. Third, it incorporates that the temptation to over-use resources is strong when more than one individual is involved. We first derive equilibrium behavior analytically and then test these pre-registered predictions in the lab. Our main results are the following: (i) Theoretically and experimentally, strategic interaction reduces cooperative behavior and undermines sustainability. (ii) Theoretically and experimentally, lowering the threshold fosters cooperation and sustainability. Our results suggest that technological advancements that lower the threshold for sustainability and behavioral change toward sustainability need not be viewed as alternatives, but rather as complementary.
Buechel, Berno and Dubois, Corinne and Fuerer, Stephanie and Bjedov, Tjasa, Sustainability as a Dynamic Game. University of Fribourg.

Reports & Other Materials