Professor: Gina A. Zurlo 
School: Harvard Divinity School 
Semester: Fall 2025

This course uses social scientific perspectives to understand religious change in the 20th and 21st centuries by investigating six dynamics: births/deaths (fertility), converts in/converts out (switching), and emigration/immigration (migration). Students will be introduced to important debates in the sociology of religion such as theories of religious change and issues related to data availability, interpretation, and communication. Relevant questions include: What data sources exist to interpret religious/non-religious global trends? Is the world becoming more or less religious? Under what conditions does an individual or community switch religions? What causes declines in fertility rates, and how do rates differ by religion? Will Islam become the world’s largest religion and, if so, by when and how? How does migration effect religious belief and practice? By investigating the six dynamics of religious change in the past, we can make reasonable assumptions for the religious and non-religious future. Four case studies detailed in the course are Christianity’s demographic shift to the global South with a focus on Nigeria, the Jewish diaspora, demography of religion in India, and religious decline in the West. Students will have the opportunity to write a final research paper or produce a demographic report.

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