Emergent extremism in a multi-agent model of religious clubs

This paper extends the club model of religion to better account for observed patterns of extremism. We adapt existing models to a multi-agent framework and analyze the distribution of agents and clubs. We find that extremism is more successful when religious groups are able to produce close substitutes for standard goods and that increased access to publicly provided goods can reduce the extremist population share. Quantile regression modeling of data from a multi-nation survey and institutional indices corresponds to the model's key results. Our findings offer a potential theoretical mechanism behind research linking terrorist origination to civil liberties.