Prediction markets for religious trends?

Might be interesting:

The survey, of 35,000 adults by telephone, offers an unusually comprehensive picture of faith among the nation's 225 million adults. This is in part because of the sheer number of people who answered questions, especially about their childhood religious affiliation. Several of the findings echo those of earlier studies, including the precipitous drop in mainline church membership and the rise in membership in nondenominational churches, the majority of which are evangelical Protestant churches.

Scholars say the Pew survey's most surprising finding is the fluidity of religious preference. The study found that 44% have left the faith in which they were raised, including Protestants who now practice another form of Protestantism and people who no longer worship at all. Sixteen percent of adults say they are unaffiliated with any religion -- including those who describe themselves as atheists, agnostics and "nothing in particular." That is double the number surveyed who say they were raised unaffiliated -- a trend noted by other religion surveys.

"Every single group in this country loses members at a considerable rate," says Luis E. Lugo, director of the Pew Forum, which conducted the study, part of the nonprofit Pew Research Center in Washington. "It is a highly competitive religious marketplace."

Protestants accounted for about two-thirds of the population in the 1970s and 1980s. Now, they make up about 51%, the Pew survey found. And of the Protestants, a quarter belong to an evangelical church, while 18% belong to a mainline church, such as Episcopal. The decline has been confirmed by other surveys of Protestants.