By John Norton

Why are U.S. Catholics leaving the Church?

It's been sometimes joked that fallen-away Catholics are numerous enough to form a denomination in their own right. Unfortunately, newly-released research from the Pew Forum on Religion and Public Life backs that up.

Here's the statistic that jumped out at me: About 10 percent of all Americans are former Catholics. That is 30 million people, or nearly equal the population of Canada.

The 140-page report, released Feb. 25, is being called one of the most comprehensive snapshots of American religious affiliation since the U.S. Census Bureau stopped asking people about their religion in the late 1950s. The survey involved phone interviews with more than 35,000 adults over a three-month period last year.

The picture it paints of Catholicism isn't flattering. A lot of people don't appear all that interested in sticking with us.

While nearly one in three Americans (31 percent) were raised in the Catholic faith, today fewer than one in four (24 percent) describe themselves as Catholic. About a third of American adults who say they were raised Catholic no longer describe themselves as Catholic.

The bottom line is that of all the religious groups in the United States, "Catholicism has experienced the greatest net losses as a result of affiliation changes."

That may come as a surprise. After all, for decades we've been told that Catholics account for roughly 25 percent of all Americans.

That number hasn't told the whole story, according to Pew.

"What this apparent stability obscures," the report says, "is the large number of people who have left the Catholic Church."

The Catholic percentage has stayed constant in part because of conversions -- 2.6 percent of the population -- but more significantly because the immigrant population is disproportionately Catholic.

"Immigration is what is keeping them afloat," John Green, a Pew senior fellow, told the Washington Times. "If everyone who was raised Catholic stayed Catholic, it'd be a third of the country."

Latinos already account for one third of adult U.S. Catholics. But that number will increase. Nearly half of all Catholics aged 18-29 are Latino.

If Latinos are keeping the Church afloat, we should be concerned that Latino Catholics are leaving the Church at a faster rate; 20 percent end up in a Pentecostal or evangelical church.

The report itself doesn't provide any clues as to why Catholics are leaving the Church. But we all know Catholics who don't practice anymore.

If you think you know why Catholics are leaving -- or better, if you have ideas on how to bring them back -- please write me at feedback@osv.com.

-- John Norton