The ARDA collection includes data on churches and church membership, religious professionals, and religious groups (individuals, congregations, and denominations).
The Pew Forum conducts surveys, demographic analyses and other social science research on important aspects of religion and public life in the U.S. and around the world.
“Hartford Seminary's Hartford Institute for Religion Research has a thirty-two year record of rigorous, policy-relevant research, anticipation of emerging issues and commitment to the creative dissemination of learning.”
"Public Religion Research Institute is a nonprofit, nonpartisan research and education organization dedicated to work at the intersection of religion, values, and public life."