Finding Data for Religious Affiliation

I had a question the other day from someone who wanted to know where they could find data for religious affiliation (i.e. the number of Catholics, Protestants, Jews, Muslims, etc in different parts of New York) on the Census Bureau's website. The answer is - no where! While it is common for census bureau's in other countries (the UK and Australia for instance) to collect this data, the US Census Bureau is prohibited by law from doing so. So where do you look?

There is an organization called the Association of Statisticians of American Religious Bodies (ASARB), where stats people from each denomination meet to pool their numbers on religious adherents in order to create a Census of Religion for the US called the Religious Congregations Membership Study, published every ten years. City College and the Grad School of Journalism have copies of it in their reference sections.

The latest data can be accessed online from the Association of Religious Data Archives (ARDA) at http://www.thearda.com/. You can generate stats on adherents at the state, county, and metro levels, and they also have summaries for nations and some basic mapping capabilities. The number of adherents in some cases is based on actual counts, and in other cases they are estimates. The quality of the estimates varies based on how thoroughly the clergy of each faith count their adherents. There is also a collection of survey data for various religious topics, everything from attitudes towards moral issues to belief in angels and life after death (there's even a question for belief in monsters!)

Here's a sample county report for New York County aka Manhattan.

- Frank