Dynamics of Religious Group Growth and Survival

Abstract

We model and analyze the dynamics of religious group membership and size. A group is distinguished by its strictness, which determines how much time group members are expected to spend contributing to the group. Individuals differ in their rate of return for time spent outside of their religious group. We construct a utility function that individuals attempt to maximize, then find a Nash equilibrium for religious group participation with a heterogeneous population. We then model dynamics of group size by including birth, death, and switching of individuals between groups. Group switching depends on the strictness preferences of individuals and their probability of encountering members of other groups. We show that in the case of only two groups—one with finite strictness and the other with zero—there is a parameter combination that determines whether the nonzero strictness group can survive over time, which is more difficult at higher strictness levels. We also show that a high birth rate can allow even the strictest groups to survive. Finally, we consider cases of several groups, gaining insight into strategic choices of strictness values and displaying the rich behavior of the model.

Resisting Education

“…Carvalho (2016) shows how oppositional groups can form to shield those who want to acquire alternative cultural traits from the transmission of mainstream traits by centralized socializing institutions (e.g., state media). Carvalho and Koyama (2016), Carvalho et al (2017), Prummer and Siedlarek (2017), and Verdier and Zenou (2018) study interventions by a single leader to shape the cultural transmission process, while Zenou (2015, 2018), Chen, McBride and Short (2019), and Carvalho and Sacks (2021) analyze competition among cultural leaders.…”

Martial races as clubs? The institutional logic of the martial race system of British India

“…Prohibitions and sacrifices serve both to screen out potential freeriders ex ante and to lower the value of their outside options relative to membership in the group. The club goods model has proven influential in the economic study of religion and has been adapted and modified in various directions since Iannocone (Aimone et al, 2013;Aksoy and Gambetta, 2016;Carvalho, 2013Carvalho, , 2016aCarvalho, , 2016bCarvalho, , 2019Carvalho et al, 2017Carvalho et al, , 2019Carvalho and Koyama, 2016;Chen et al, 2019;McBride, 2015McBride, , 2016. The club goods model has also been extended to conflict scenarios by Berman (2008Berman ( ), (2011, who used it to explain the success of modern day religious terrorist and insurgent groups such as the Taliban and Hezbollah.…”