I love poring over data on U.S. religions, and a motherlode of such data can be found on the Web site of The Association of Religion Data Archives (ARDA).
Tonight, I’ve been looking over religion data for Santa Clara County, the county which includes the UU Church of Palo Alto, as found in the County Membership Report.
ARDA’s Web page shows that 43.6% of the county population are religious adherents, essentially unchanged from 43.3% of the county’s population in 2000. The count includes 1,005,614 people as unaffiliated; 447,369 as Roman Catholic; 148,599 as Evangelical Protestant; 125,165 as Other (this includes Buddhists, Hindus, Jews, UUs, etc.); and 44,623 as Mainline Protestant. 927 people are counted as members of Unitarian Universalist congregations.
These counts are based on self-reporting by 236 religious bodies, and any interpretation should take that into account. Obvious problems: religious bodies may have different reporting procedures; some of us (like me) are regular attendees but are not official members of a congregation, so are not counted; counts may include people who are not really adherents; etc.
The basic data sets come from the Assoc. of Statisticians of American Religious Bodies, whose Web site is also of interest.
My main interest in the ARDA Web page is how it helps show the incredible religious diversity of Santa Clara County. Admittedly, they miss some smaller religious groups, particularly adherents of Orisa Devotion, and several New Religious Movements; but these are groups that may deliberately hide from, or give incorrect information to, researchers. Even with the obvious gaps (Cao Dai, Scientology, Santeria), their list of religious groups shows impressive diversity: a bewildering variety of Christians; Baha’is; Buddhists; Hindus; Jains; Jews; a few New Religious Movements; Sikhs; and Unitarian Universalists.
Definitely a fascinating Web site for exploring data on religion in a given geographical region.