Peace in an unequal world

Using a student sample, we experimentally investigate whether (unarmed) peace can be sustained if conflicting parties (players) can reduce existing resource inequalities, compared to a situation where they cannot.

We run two experimental conditions of a two-player winner-takes-all conflict (guns-vs-butter) game. In both conditions, a disadvantaged player starts with 80 Tokens, while an advantaged player starts with 120 Tokens. The conditions differ in the ability to transfer resources to another player. In one condition (UNEQUAL) they cannot transfer parts of their resources to the other player, while they can do so in the other (TRANSFER).

Our design allows us to experimentally investigate whether transfers are used to reduce existing inequalities and whether this leads to more peaceful outcomes.

We run two experimental conditions of a two-player winner-takes-all conflict (guns-vs-butter) game. In both conditions, a disadvantaged player starts with 80 Tokens, while an advantaged player starts with 120 Tokens. The conditions differ in the ability to transfer resources to another player. In one condition (UNEQUAL) they cannot transfer parts of their resources to the other player, while they can do so in the other (TRANSFER).

Depending on funding, we will run 4 (or 5) sessions with 14 participants in both experimental conditions, grouped into one cluster, resulting in 56 (70) participants per experimental condition.

2025-01-07

2025-01-31

Decisions on whether to start a conflict and consequently the emergence of conflicts
Investments in conflicts

In every round, players decide whether to start a conflict ("tournament"). If at least one of the two players decides to start a conflict, both players enter a conflict. If both decide against a conflict, peace prevails.

At the same time, they decide how to divide their resources between production and arming (the investment in conflict).

Belief about the decisions (starting conflicts, and investment in conflicts) of other player
Amount transferred to other players (only in TRANSFER)

In the first of seven periods, we elicit players beliefs about the decisions of the other player

The experiment will be conducted at the Lab of the Technical University of Munich (experimenTUM). Building on the model by Garfinkel and Syropoulos (2021), we employ an experiment with students in the role of conflicting parties who play the game for 7 rounds. Since we are interested in a one-period setting, we randomly re-match parties after each period, ensuring that the same pair of players will only meet once, therefore impeding reputation-building between players.

We will conduct two experimental conditions. We will run 4 (or five) sessions with 14 participants, grouped into one cluster, in every experimental condition. The conditions differ in the ability to transfer resources to another player. In one condition (UNEQUAL) they cannot transfer parts of their resources to the other player, while they can do so in the other (TRANSFER).

References:
Garfinkel, M. R. & Syropoulos, C. (2021). Self-enforcing peace agreements that preserve the status quo. Games and Economic Behavior, 130, 148–178

The experiment will be conducted at the Lab of the Technical University of Munich (experimenTUM). We build our experimental design on the model by Garfinkel and Syropoulos (2021).

The experiment will be divided into seven parts:

1 Short Questionnaire
2 Loss Aversion Task (Gächter et al., 2022)
3 Trust Game (Berg, Dickhaut & McCabe., 1995)
4 Distribution Task (Fehr, Epper & Senn, 2024)
5 Guns and Butter Conflict Game - Experimental Variation (UNEQUAL & TRANSFER)
6 Trust Game (Berg, Dickhaut & McCabe., 1995)
7 Short Questionnaire (Demographics)


The Guns and Butter Conflict Game:

The basic structure of the game is as follows:

[only in TRANSFER:] At the beginning of every period, players can transfer parts of their resources to the other player.
[in both experimental conditions:] In every period, players are asked to allocate their resources between tournament and production and indicate whether they want to start a tournament or not. Additionally, in the first period, we elicit whether respondents believe that the other party will start a tournament.

If both parties abstain from starting a tournament, their payoffs in the respective period are simply their investments in production. If at least one party starts a tournament, both enter and their payoffs are determined in a destructive winner-take-all tournament, where the investments into conflict determine the probability of winning. The destructiveness of a conflict is 55\%. At the end of the game, one out of the 7 periods will be randomly drawn and participants get paid their payoffs generated in this period.

Given the random assignment of respondents to the experimental groups, we can use multilevel mixed-effect regressions to estimate causal treatment effects. We use mixed-effects models to account for dependencies between observations on the session, group, and individual levels.

We will test the following two main hypotheses:

Hypothesis 1.
H0: Players are equally likely to start a conflict in both experimental conditions
H1: Players are NOT equally likely to start a conflict in both experimental conditions

Hypothesis 2.
H0: Players invest the same amount of resources in the tournament in both experimental conditions
H1: Players invest different amounts of resources in the tournament in both experimental conditions

References:
Berg, J., Dickhaut, J., & McCabe, K. (1995). Trust, reciprocity, and social history. Games and economic behavior, 10(1), 122-142.
Fehr, E., Epper, T., & Senn, J. (2024). Social preferences and redistributive politics. Review of Economics and Statistics, 1-45.
Garfinkel, M. R. & Syropoulos, C. (2021). Self-enforcing peace agreements that preserve the status quo. Games and Economic Behavior, 130, 148–178
Gächter, S., Johnson, E. J., & Herrmann, A. (2022). Individual-level loss aversion in riskless and risky choices. Theory and Decision, 92(3), 599-624.

Randomization is carried out in the experiment by a computer software.

Experimental Session

Yes

4-5 clusters ́a 14 individuals in UNEQUAL
4-5 clusters ́a 14 individuals in TRANSFER

112 - 140 participants

56 (or 70) participants in UNEQUAL
56 (or 70) participants in TRANSFER

We performed a power analysis based on the results of our previous experimental study (Baier, Seelos & Rittmannsberger, 2024). In this study, the authors vary the resource inequalities between players (EQUAL vs. UNEQUAL). Assuming a similar effect in the probability of conflict across our treatments, we will need 56 subjects to ensure a power of at least 80% for a significance level of 5%. Reference: Baier, A., Seelos, S., & Rittmannsberger, T. (2024). Peace in an unequal world? Experimental evidence on the relationship between inequality and conflict in a guns-vs-butter setting. Games and Economic Behavior, 147, 74-87.