I was recently looking for some stuff at the Census Bureau when the Top 5 Data Links there caught my attention in the Statistical Abstract. Table 74, Self-Described Religious Identification of Adult Population: 1990 and 2001, was the fifth most popular data link. You can examine the table in PDF if you like.
The results come from the American Religious Identification Survey (ARIS). The researchers called 50,000+ random phone numbers in the 48 continental United States. This survey tapped subjective self-identification, asking people to what religion they saw themselves belonging
How many Baha'is did the survey find? Well, in 1990 the survey estimated 28,000 Adult Baha'is, and in 2001 that figure was up to 84,000. The figure of 84,000 sounds more plausible than the 28,000 figure for 1990. I've worked in organizing voting meetings for my area of Baha'is, so I was able to examine the list of all enrolled Baha'is in my area of Illinois. Knowing that the voting areas have approximately the same number of Baha'is in them, and knowing how many voting areas there are, allowed me to estimate how many Baha'is were on the rolls (and how many of those were active). I also reached a conclusion that there would be slightly over 100,000 Baha'is, of whom the majority (about four-fifths) were adults, and so the 84,000 figure for adult Baha'is fits with that. But, I don't think the Baha'i community has grown dramatically between 1990 and 2001. So, this calls into doubt all the figures from this survey. Of course in a study like this the measurement errors are much higher for the little groups, so the confidence interval for a group like the Baha'is who make up 0.05% of the adult population must be fairly large relative to the bigger denominations. You can read more about the study at this website about the ARIS study.
The big groups are Catholics with about 51 million adult believers in 2001, the Baptists with 34 million adults, and the Methodists with 14 million adults. About 160 million adults, about 77% of American adults, self-identified as Christian. About 1.4% of adults were self-identifying as Jewish, and about half of one percent self-identified as Muslim. What about Atheists and agnostics? If you combine those two and add "humanist" and "secular" and "no religion" you get about 29.5 million, or slightly over 14% of American adults. The number in that category more than doubled between 1990 and 2001.
I wish the Baha'is had as many believers as the other minority religions like the Jewish, Muslim, or Buddhists. You can get some really interesting dynamics and activities in a community of over a million believers. You just can't get the same style of community life in a national community with maybe 60,000 active believers and another 50,000 fairly inactive ones. Hey, reader, have you examined the Baha'i Faith? Despite it's faults (the same sort of faults you'll find in any organized religion or association of humans) I'm a believer and quite satisfied with identification with it. Maybe you would like to know more?