Heidemarie Winkel is a professor of sociology at Bielefeld University in Germany. She’s also a senior research associate with the Von Hugel Institute for Critical Catholic Inquiry at the University of Cambridge.

Katja Rakow is an assistant professor of religious studies at Utrecht University in the Netherlands. She studies Christian megachurches in the United States and Singapore and contemporary Pentecostalism more broadly.

Davis Voas is a professor of social science at University College London, where he studies religious change.  He helps lead the European Values Survey and British Religion in Numbers project.

Scott McConnell is the executive director of LifeWay Research, which conducts surveys on issues affecting American religious life and Protestant pastors. Arrange an interview through Aaron Earls.

Jennifer McClure is an assistant professor of religion at Samford University in Birmingham, Ala. She is also the senior associate for congregational resources with the Association of Religion Data Archives and consults with congregations on organizational health.

Bethamie Horowitz is co-director of the programs in education and Jewish studies at New York University. She also has a research and consulting practice and has spent the last two decades tracking major issues facing the Jewish community.

The Rev. Randy Wall is senior pastor of New Covenant United Methodist Church in Mount Holly, N.C. He’s also the chairman of United Methodist Rural Advocates, a group that advocates on behalf of rural and small-membership churches within the denomination.