Cooperation and punishment in a nationwide experiment

We investigate whether cooperation rates increase through the implementation of a third-party punishment (TPP) mechanism. Therefore, we plan to run a large-scale artefactual field experiment with a nationally representative sample of the German population, where participants play an incentivized prisoner dilemma (PD) game.

To do so, we run two experimental treatments. In the first treatment, there is no TPP, while in the second treatment, TPP is possible. We randomly divide all participants into two groups. The first group is assigned to the first treatment and plays the PD game without TPP, while the second group is assigned to the second treatment and plays the PD game with TPP.

2023-08-08

2023-08-25

Cooperation rate in the PD game: The share of participants who decide to send their endowment to their partner [Question q01].

We will analyze beliefs concerning the decision of the other player: the share of participants believing that their partner decides to send [Question q02].
In treatment 2 (with TTP) we will analyze the beliefs concerning the decisions of the referee [Questions q05 & q06].
Furthermore, we will investigate effect-heterogeneities by age, gender, and socioeconomic status, as well as whether respondents answered the control questions correctly and whether they self-report having understood the instructions of the game [Question p26]. Furthermore, we will investigate the correlation between cooperation and punishment decisions and survey-based measures of real-life (cooperative) behavior in the context of health [Questions p09-p13] and the environment (where we build an index from the Questions p01-p08).

We plan to sample a minimum of 2,000 adults aged between 18 and 69 years (up to a maximum of 2,500 — conditional on final costs; also see “Experiment characteristics”).
The experiment is conducted in cooperation with a survey institute. The recruitment and polling are managed by the survey institute. We collect the data via an online platform (QUALTRICS). Our participants take part in the experiment autonomously on their own digital devices. Randomization is carried out by the survey institute at the individual level, using a computer. Payment of incentives is carried out anonymously by the survey institute.
Our experiment is structured as follows:
Respondents will be randomly assigned (between subjects) to Treatment 1 (p=0.5), or Treatment 2 (p=0.5).

Treatment 1 (with TTP):
Stage 1: Cooperation
Stage 2: Beliefs about the behavior of the partner
Stage 3: Appropriateness of decisions
Stage 4: Beliefs about the behavior of the referee
Stage 5: Personal questions

Treatment 2 (without TTP):
Stage 1: Cooperation
Stage 2: Beliefs about the behavior of the partner
Stage 3: Appropriateness of decisions
Stage 4: Punishment Decision
Stage 5: Personal questions

Randomization is carried out by the survey company, using a computer.

At the individual level

No

2,000 individuals (adults aged between 18 and 69 years). (maximum: 2,500 – conditional final costs)

2,000 individuals (adults aged between 18 and 69 years). (maximum: 2,500 – conditional final costs)

2,000 individuals (1,000 per treatment). (maximum: 2,500 (1,750/1,750) – conditional on final survey costs).
According to our conservative cost calculations, we have sufficient funding for sampling 2,000 individuals. Depending on the final costs of the survey, we envisage continuing sampling up to a maximum number of 2,500 individuals.