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.

Participants will conduct the experiment via an online platform.
Participants will be randomly assigned to one of two experimental groups, and each participant takes decisions in five consecutive stages.
We inform them, that they must answer several control questions and that they cannot participate in the survey if they fail to answer them correctly.

[Experiment Wording]

With this survey, we would like to learn more about the attitudes of the population in Germany towards various topics. Answering the questionnaire will take about 15 minutes. The survey is anonymous, and your answers will be treated with absolute confidentiality. The anonymized dataset containing the responses of all participants will be made available to the scientific community exclusively for research purposes. By clicking "Continue" below, you agree to this provision. No conclusions can be drawn about your personal identity from the data.

We are simply interested in your spontaneous assessments and opinions. Therefore, please provide an answer even if you are unsure. By clicking the "Continue" button, you will proceed to the next question.

This survey includes a game in which you can earn additional compensation. To participate in the game, you must read a short game instruction and answer several comprehension questions correctly. Any additional compensation will be credited to you within the next four weeks after the data analysis.

To facilitate comprehensibility, we use the male form in the game instructions. However, all personal designations used equally apply to women, men, and diverse genders.

Thank you in advance for your participation at this stage!

[Game Instructions: Same in both experimental conditions]

In the following sending game, you have the opportunity to earn additional compensation. The amount of compensation depends on your decisions and the decisions of other participants.

For the following decisions, we will assign you a "partner". This partner is a randomly selected participant in this survey. The participants represent the overall population in Germany as accurately as possible and fall within the age range of 18 to 69.

In the sending game, you will receive 1 euro and must decide whether to "send" or "not send" the euro to your partner.

If you decide to "send" the euro, it will be doubled, and your partner will receive 2 euros.

If you decide "not to send" the euro, you will keep 1 euro.

Your partner will also receive 1 euro and must decide whether to "send" or "not send" it back to you. The same rules apply.

Both you and your partner make your decisions simultaneously, so neither of you can see how the other person decides.

[4 COMPREHENSION QUESTIONS - respondents have 3 attempts - if they fail they cannot continue with the survey]
[Answer categories:] Open answer – numbers.

How much do you and your partner earn in the following situation?
[C1] Assume you and your partner decide to"send".
[C2] Assume you decide to "send", your partner decides "not to send".
[C3] Assume you decide "not to send", and your partner decides to "send
[C4] Assume you and your partner decide "not to send".

[START: TREATMENT VARIATION]

[Group 1: START: Treatment WITH TTP]

ATTENTION: There is an additional rule of the game.

There are referees in this game. You and your partner each have one referee. They each get 0.5 euro initial budget. Your referee observes your decisions and must decide whether or not to take away all of your earnings from the sending game.

He may choose to take away your earnings from the sending game. In this case, you lose all the earnings from the sending game and get no money. However, this will cost the referee 0.5 euros and will be deducted from his initial budget. ATTENTION: Nobody gets the money taken away. Not even the referee.

He may also choose not to take away your earnings from the sending game. In this case, you keep all the earnings from the sending game.
This costs the referee nothing and he keeps his initial budget of 0.5 euros.

Since your referee cannot observe your decision directly, he has to make two separate decisions. Once for the case that you choose "not to send" and once for the case that you choose "send".

Your referee is not your partner from the sending game, but another randomly selected participant in this survey.

The same rules of the game apply to your partner and his referee.

[6 COMPREHENSION QUESTIONS - respondents move automatically on after the 3 attempts]

ATTENTION: The sending game begins now! Please make your decision in the sending game now!

[Stage 1: Cooperation]
[q01] Which decision do you want to make? [Answer Categories: Send / Don't Send]

[Stage 2: Beliefs about the behavior of the partner]
[q02] What do you guess your partner's decision is? [Answer Categories: Send / Don't Send]
[q02a] How confident are you that your answer is correct? [Answer categories: 7-point scale: (1) “Very unconfident” … (7) “Very confident”]

[Stage 3: Appropriateness of decisions]
[q03] How appropriate or inappropriate do you think it is to choose "send" in the previous game?
[Answer Categories: (1) "Very inappropriate"; (2) "Somewhat inappropriate"; (3) "Somewhat appropriate"; (4) "Very appropriate"]
[q04] And how appropriate or inappropriate do you think it is to choose "\textbf{don't send}" in the previous game?
[Answer Categories: (1) "Very inappropriate"; (2) "Somewhat inappropriate"; (3) "Somewhat appropriate"; (4) "Very appropriate"]

[Stage 4: Beliefs about the behavior of the referee]
[q05] What do you guess your referee will decide if you choose "send"? [Answer Categories: Don't take away/ Take away]
[q05a] How confident are you that your answer is correct? [Answer categories: 7-point scale: (1) “Very unconfident” … (7) “Very confident”]

[q06] What do you guess your referee will decide if you choose "don't send"? [Answer Categories: Don't take away/ Take away]
[q06a] How confident are you that your answer is correct? [Answer categories: 7-point scale: (1) “Very unconfident” … (7) “Very confident”]

[Group 1: END: Treatment WITH TTP]

[Group 2: START: Treatment WITHOUT TTP]

ATTENTION: The sending game begins now! Please make your decision in the sending game now!

[Stage 1: Cooperation]
[q01] Which decision do you want to make? [Answer Categories: Send / Don't Send]

[Stage 2: Beliefs about the behavior of the partner]
[q02] What do you guess your partner's decision is? [Answer Categories: Send / Don't Send]
[q02a] How confident are you that your answer is correct? [Answer categories: 7-point scale: (1) “Very unconfident” … (7) “Very confident”]

[Stage 3: Appropriateness of decisions]
[q03] How appropriate or inappropriate do you think it is to choose "send" in the previous game?
[Answer Categories: (1) "Very inappropriate"; (2) "Somewhat inappropriate"; (3) "Somewhat appropriate"; (4) "Very appropriate"]
[q04] And how appropriate or inappropriate do you think it is to choose "\textbf{don't send}" in the previous game?
[Answer Categories: (1) "Very inappropriate"; (2) "Somewhat inappropriate"; (3) "Somewhat appropriate"; (4) "Very appropriate"]

Now we come to a new game:

In this game, you are a referee. For this, you will receive 0.5 euro initial budget. You observe the decision of another participant in the previously described broadcast game with slightly changed rules. You have to decide whether you want to take away or not take away all his earnings from the sending game. You can choose to take away the participant's earnings from the sending game. In this case, he will lose all the earnings from the sending game and will not get any money. However, this will cost you take away and will be deducted from your initial budget. ATTENTION: Nobody gets the money taken away. Not even you as a referee.

You can also choose not to take away the participant's earnings from the sending game. In this case, he keeps all the earnings from the sending game. This will cost you nothing and you will keep your initial budget of 0.5 euros.

Since you don't know now which decision this participant will make, you have to make two separate decisions. Once for the case that he chooses "don't send" and once for the case that he chooses "send".

This participant is not your partner from the sending game, but another randomly selected participant from this survey.

Important: The rules of the game with the possible loss of earnings are known to this participant when he makes his decision in the sending game.

Also, the partner of this participant has his own referee who can take money away from him.

[6 COMPREHENSION QUESTIONS - respondents move automatically on after the 3 attempts]

ATTENTION: Now comes the referee decision! Please make your decision now!

Since you don't know yet which decision this participant will make, you have to make two separate decisions. Once for the case that he chooses "don't send" and once for the case that he chooses "send".

[Stage 4: Punishment Decision]
Which decision do you want to make?

[q07] If the participant chooses "don't send", I would like to ... [Answer Categories: .. take away / ... don't take away]
[q08] If the participant chooses "send", I would like to ... [Answer Categories: .. take away / ... don't take away]

[Group 2: END: Treatment WITHOUT TTP]

[END: TREATMENT VARIATION]

[Stage 5: Personal questions ]

___

[Treatment Variation]
Participants are randomly assigned to one of two treatments groups and play two different versions of the game:
[Treatment Group 1] — Prisoners' Dilemma with TPP
[Treatment Group 2] — Prisoners' Dilemma without TPP

Please refer to the provided supplementary material for the complete translated survey: Translated online survey for pre-registration_PD_Game

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.