Because this study invites religious bodies to participate, not every group chooses to participate, or is able to do so. This becomes evident when one compares the participants in the 1990 and 2000 studies; there are 95 groups that participated in both studies, 54 groups that participated in 2000 but not 1990, and 37 that participated in 1990 but not 2000.For comparison, note that the Episcopal Church USA had 2.5 million adherents in 2000, making it the 10th largest denomination reporting figures to RMCS.
It is worth noting that most of the largest groups do participate, so that the authors are confident in saying that the vast majority of people associated with a congregation are represented within the study. This claim is supported by the fact that the 141,371,963 adherents reported at the county level in RCMS 2000 represents 94% of the national inclusive membership total reported by the Yearbook of American and Canadian Churches 2001.
There are, however, 14 groups that reported more than 100,000 inclusive members to the Yearbook of American and Canadian Churches that did not participate in the RCMS 2000 study. These groups include:
Denomination / Membership
African Methodist Episcopal Church / 2,500,000
African Methodist Episcopal Zion Church / 1,276,662
Baptist Bible Fellowship / 1,200,000
Christian Brethren / 100,000
Christian Congregation, Inc. / 118,209
Christian Methodist Episcopal Church / 784,114
Church of God In Christ / 5,499,875
Full Gospel Fellowship of Churches and Ministers International / 325,000
Jehovah's Witnesses / 990,340
National Baptist Convention of America, Inc. / 3,500,000
National Baptist Convention, USA, Inc./ 8,200,000
National Missionary Baptist Convention of America / 2,500,000
Pentecostal Assemblies of the World, Inc. / 1,500,000
Progressive National Baptist Convention, Inc./ 2,500,000
Many of the groups listed above are historically African American religious bodies. The absence of these bodies must be considered when studying religious adherence within areas of the country with a significant African American population.
The absence of African-American church members must be considered when studying religious adherence across counties. For instance, counties with large black populations may have a large number of adherents uncounted and a low rate of economic growth. The importance of adherence in economic growth could be biased upwards.
Question: Why did a disproportionate number of African American religious bodies not participate? Was it lack of resources, culture, distrust?