Counting Catholics: How do demographers estimate the American Catholic population?

Why Is It So Hard to Count the Catholic Population?

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March 20 2013 3:44 PM

One Catholic, Two Catholics, Three Catholics ...


Nuns from the 'Instituto Serve del Signore, E Della Vergine Di Matara,' (Servants of the Lord and the Virgin of Matara,) react to the black smoke.

Photo by Dan Kitwood/Getty Images

Vice President Biden attended the installation of Pope Francis at the Vatican on Tuesday, representing the tens of millions of Catholics living in the United States. Precise estimates of American Catholics vary from 57 million to 78 million. How do you count Catholics?

Surveys, sacraments, or church records. The total number of American Catholics depends largely on what you think it takes to be a Catholic, with the numbers dropping as the required level of commitment increases. It takes very little effort to self-identify as a Catholic, so the Pew Research Center’s survey sets the Catholic population high at 75 million. The Catholic Research Forum has more rigorous standards, defining Catholics as people who are baptized into the church and arrange for a Catholic funeral. By this measure, there are approximately 68 million American Catholics. Finally, some demographers count only people who register at a church or regularly attend Mass. The U.S. Religion Census: Religious Congregations & Membership Study, which asked local church leaders to estimate the number of people in their congregations, set the American Catholic population at just 59 million. Weak church attendance accounts for this discrepancy: Only 24 percent of self-reported American Catholics attend Mass weekly. (Another church-generated estimate, the Official Catholic Directory, estimates the national flock at 66.3 million, but critics worry that clerics inflate the numbers for this publication for PR reasons.) What do these numbers mean? There’s a population of approximately 19 million Americans who think they’re Catholic but who are unknown to their local priests.

None of these methods accurately captures the Vatican’s view of the Catholic population. Under church law, baptism makes you a Catholic, and you remain a Catholic until you’re excommunicated or formally repudiate the faith. Since more people unilaterally abandon Catholicism than join it without baptism, the Vatican’s census is typically even higher than the number of self-identified faithful. The official Statistical Yearbook of the Church counts a total of 1.196 billion Catholics worldwide, or 96 million more than Pew does, a difference of about 9 percent. Variances within individual countries can be far more extreme. The Vatican’s estimate for Brazil is 29 percent higher than Pew’s.




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