Leaving together: social influence and church decline

Abstract

Church membership has declined across much of the Western world in recent decades. Existing research has identified individual characteristics that affect individuals’ likelihood of leaving their churches, but far less is known about how social interactions influence church decline. We examine (1) how exposure to others leaving the Church of Sweden affects individuals’ likelihood of leaving and (2) the aggregate membership dynamics generated by these micro-level processes. Using full-population register data from 2002 to 2023 and a dynamic matched-sample design, we estimate social-influence effects and assess how susceptibility varies with religious embeddedness, defined as the extent to which individuals are socially connected to other church members. We use these estimates to calibrate an agent-based simulation model linking individual behavior to aggregate membership decline. The results show that exposure to leavers increases individuals’ likelihood of leaving the Church, particularly among those with weak religious embeddedness. The simulations indicate that social influence contributed appreciably to the numerical decline of the Church of Sweden, while religious embeddedness moderated this effect. Social influence can thus amplify ongoing religious decline, while religious embeddedness attenuates this amplification.