Date of Award


Document Type

Open Access Dissertation



First Advisor

Brent T Simpson


Most work on groups facing collective action assumes that group membership is static, or fixed. Yet static membership is rare, with members joining and leaving groups. In this thesis, I propose to explore how the presence of newcomers to groups affects group coordination. Past research has shown an overall negative effect of newcomers on group contributions. The proposed thesis attempts to further establish the effect by determining whether newcomers, oldtimers, or both are responsible for the declining cooperation in groups. While the empirical component is focused solely on establishing who is responsible for driving down cooperation rates in dynamic groups, the paper also discusses several potential mechanisms driving lower cooperation rates. When considering newcomers, the thesis addresses the potential impact of group norm knowledge, group commitment and identification, and the role of status. Potential mechanisms driving oldtimers' lower cooperation behavior considers trust and anonymity.