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arXiv · 2609.06151

Ripple Effects: Robust Norms without Punishment

Alistair Barton
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Abstract

I propose a novel, tractable model of pro-social norms in large communities with slightly altruistic agents. Agents participate in the norm to influence others to participate in the norm, influencing further agents. A continuum of equilibria sustain the pro-social norm, varying in the distribution of how much agents are influenced by their observations. If agents' effective altruism $\alpha$ is larger than their impatience $1-\delta$, equilibria exist that are robust to a population of bad actors. Greater strategic homogeneity increases the robustness of the norm. Robustness is not improved by increasing the number of observers of each action beyond 1.

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Alistair Barton. 2026-09-05. Ripple Effects: Robust Norms without Punishment. https://arxiv.org/abs/2609.06151

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