Think fast: How many Americans went to church last Sunday? Forty percent? Twenty percent? Somewhere in between?
Whatever the guess, it might be right.
For years, some polling groups and sociologists who specialize in tracking the religious behavior of Americans have been at odds trying to get a handle on how many of us go to worship services on a regular basis.
Two of the best-known names in religion polling _ the Gallup Organization and Barna Research Group _ say about four in 10 Americans go to church weekly, a figure that has remained fairly consistent since 1939, when Gallup first began collecting such data.
But sociologists C. Kirk Hadaway, Penny Long Marler and Mark Chaves say in the February 1998 issue of the scholarly journal American Sociological Review that if actual heads were counted each Sunday, just 20 percent of Americans would be found in church.
In Overreporting Church Attendance in America: Evidence that Demands the Same Verdict, the authors blame over-reporting of church attendance by survey respondents as the primary reason for a major gap between their findings and the poll-based estimates.
"Most sociologists tended to think there was a little bit of a gap between what people said and what they did . . . but we didn't see how large the gap was until we began (counting attendance) ourselves in 1992," said Hadaway, a United Church of Christ official who has tracked church membership and attendance trends for 20 years.
"Our initial study, which was based on attendance counts of Protestants in one Ohio county and Catholics in 18 dioceses, indicated a much lower rate of religious participation than the polls report," he said. "Instead of 40 percent of Protestants attending church, we found 20 percent. Instead of 50 percent of Catholics attending church, we found 28 percent."
The sociologists counted people in pews and cars in church parking lots and studied attendance reports provided by pastors in Ashtabula County, Ohio, a Midwest region generally indicative of churchgoing trends for the nation, Hadaway said.
Despite these findings, David Kinnaman remains confident in the 43 percent church-attendance rate the Barna Research Group came up with for 1998.
"We totally stand by our numbers. They are arrived at with ongoing research," said Kinnaman, research director at Barna.
But Hadaway and his colleagues believe some data-gathering methods are more reliable than others.
"We believe that too much trust has been placed in survey data and not enough attention given to membership records, patterns of giving and even the incredulity of local church pastors when they hear that 40 percent of Americans attend church during an average week," said Hadaway.
Robert Woodberry, a sociologist at the University of North Carolina, Chapel Hill, who has studied churchgoing trends for three years, has serious reservations about the methodology used by Hadaway and his colleagues.
In counting Catholic attendance, for example, Hadaway, Marler and Chaves did not include Eastern Rite Catholics, or those who attended Mass at a venue other than a parish church, such as at shrines, hospital chapels or on college campuses, he said.
At the same time, Woodberry is critical of trying to determine who goes to church by asking questions over the telephone, as Gallup and Barna do.
"Most polls over-sample regular church attenders and so over-represent their opinions," he said, adding that regular churchgoers are generally easier to contact at home, are more cooperative in answering surveys and don't mind telling pollsters about their religious activities.
Kinnaman rejected Woodberry's claim, saying he has never seen reliable data to suggest regular churchgoers are over-sampled.
Even with its inherent complexities, Hadaway prefers the head-counting method over polling because he questions whether Americans reliably report their activities to pollsters.
"How much trust should we put in what people say they do? Perhaps not as much as we have up to this point," said Hadaway. "Numerous studies show that Americans misreport voting, gifts to charities, and illegal drug use. And their misreporting is in the expected direction: higher for voting and charity giving; lower for drug use.
One thing is certain: Analyzing mounds of data mixed with a seemingly infinite quantity of unknowns makes calculating the exact number of Americans who attend church weekly an arduous assignment at best.
"It is a formidable task," agreed Hadaway. "But by putting together all the information, you can make some summary judgment."