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Climate Action as a Coordination Game: Evidence from the Fridays for Future Movement
Last registered on December 19, 2019


Trial Information
General Information
Climate Action as a Coordination Game: Evidence from the Fridays for Future Movement
Initial registration date
September 04, 2019
Last updated
December 19, 2019 9:53 AM EST
Primary Investigator
University of Hamburg
Other Primary Investigator(s)
PI Affiliation
University of Hamburg
PI Affiliation
University of Hamburg
Additional Trial Information
Start date
End date
Secondary IDs
On September 20, 2019, the “Fridays for Future” movement calls for worldwide climate strikes. The German branch of the movement addresses all age groups in its call and explicitly asks adults to join the protests that day. The decision to protest can be viewed as strategic, depending on individual beliefs about others’ participation. We will conduct a framed field experiment in the context of this global climate strike to test the hypotheses that (i) the decision to participate in climate action is a strategic complement to others' turnout and (ii) that the magnitude of strategic complementarity is conditional on social distance.
The experimental design follows the study of Cantoni et al. (Quarterly Journal of Economics, Vol. 134, pp. 1021-1077). They focus on the antiauthoritarian movement in Hong Kong and find evidence that the decision to join the protests is a game of strategic substitutes, i.e., people are less willing to join when they believe more others will do so. Nevertheless, Cantoni et al. stress the heterogeneity across political topics and suggest investigating the protest game in various settings.
In this study, we re-investigate the impact of updated beliefs on individual protest decisions in a different context. In addition, our study goes beyond a replication for two reasons. First, in contrast to the findings of Cantoni et al., we hypothesize that for the movement on climate action the individual protest decision is a strategic complement to others’ participation. While the antiauthoritarian protest in Hong Kong may be considered a public good itself, providing a signal to the regime by its mere existence, we expect that for climate action protest, the public good is the ultimate success of the movement, i.e. the change in climate policy. As the protest’s success monotonically increases with turnout, we hypothesize that people are more willing to join when they believe more others will do so.
Second, we expand the experiment reflecting the fact that “Fridays for Future” started and is still perceived as a youth movement. Given the focus on age, our second hypothesis is that the magnitude of strategic complementarity depends on the characteristics of other potential participants, in this case others’ age. We expect that subjects are more responsive to the age-related peer group.
To test our hypotheses, we will conduct an experiment with three stages. First, we will ask residents in the four largest German cities before the event about their planned participation in the upcoming local event and their beliefs about others’ planned participation. In the second stage, we will provide a random subset of subjects with truthful information about others’ planned participation before the event that we have derived from the first round. To reflect the focus on adults in this call for protest, we will provide another subset of subjects with additional truthful information about a certain age groups’ planned participation. Subjects receiving the interventions can update their beliefs about others’ participation and incorporate it in their decision to participate. After the event, we elicit subjects’ actual participation. This allows us to identify the causal effects of positively and negatively updated beliefs about others’ event participation on subjects’ own turnout.
External Link(s)
Registration Citation
Jarke-Neuert, Johannes, Grischa Perino and Henrike Schwickert. 2019. "Climate Action as a Coordination Game: Evidence from the Fridays for Future Movement." AEA RCT Registry. December 19. https://doi.org/10.1257/rct.4583-1.2000000000000002.
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Experimental Details
The study contains a total of three treatments including the control treatment. In each treatment, subjects are asked to state their own planned participation in the local event and to estimate other subjects’ planned and actual participation. After the first stage, we will calculate the average share of subjects planning to participate based on their stated own planned participation.
Providing this average share to two random subsets of subjects represents the treatments. The treatments will be implemented in the second stage. One random subset of subjects will receive the average share of all subjects from age 18 to 69 who plan to participate. Another random subset of subjects will additionally receive the average share of subjects from age 30 to 69 who plan to participate. The average shares are both truthful information. Their derivation will be explained to subjects when they receive the information. We (the research team) will have no impact on the numbers that will be provided to the two treatment groups. After receiving the truthful information, subjects can update their prior estimates about other subjects’ actual participation in the local event if they want to.
Subjects in the control treatment do not receive any information on other subjects’ planned participation from the first stage, but they can also update their prior estimates about other subjects’ actual participation.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Stated ex ante likelihood of participating in the local event (4-point scale); beliefs regarding others' planned and actual participation before the event (percentage of survey participants); actual decision to participate (categorial scale) in the global strikes on September 20th and November 29th, 2019
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Between-subjects randomized trial with one control and two treatment conditions.
Experimental Design Details
Randomization Method
Computer quasi-randomization
Randomization Unit
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
4 cities
Sample size: planned number of observations
1,200 individuals at three dates, respectively
Sample size (or number of clusters) by treatment arms
400 individuals control, 400 individuals standard treatment, 400 individuals age-specific treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
The Dean's Office of the Faculty of Business, Economics and Social Sciences at Universität Hamburg
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Intervention Completion Date
September 19, 2019, 12:00 AM +00:00
Is data collection complete?
Data Collection Completion Date
December 16, 2019, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
1,510 individuals
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
1,510 individuals
Final Sample Size (or Number of Clusters) by Treatment Arms
484 individuals in the control condition / 1,026 individuals in the treatment condition, of which 530 individuals got only the "general" treatment and 496 individuals got the additional "age" treatment
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)