RCMS 2010: Catholic Appendix A

Catholic Church [Catholic]

Contact person(s): Clifford Grammich
Date of statistics: 2010

  • Definition of congregations: Parish churches, mission churches, and some limited locations with regularly scheduled weekend Masses that may be considered regularly meeting Catholic congregations equivalent to other congregations in this study.
  • Definition of adherents: "Adherents" are generally equivalent to the number of baptized Catholic individuals known to each parish or mission church. For the 2010 study, each diocese was asked to provide, by parish or mission, their number of registered households, registered individuals, infant baptisms within the past year, deaths within the past year, and weekly attendance. This was part of an effort to provide a more congregational-based definition comparable to those of other religious bodies in the study. Put another way, the number of "adherents" is roughly equivalent to those who are known in some way to each parish or mission.
  • Comments on the accuracy of the statistics: Altogether, this work enumerated nearly 59 million Catholics known in some way to each parish or mission in the United States. This number is substantially below two common measures of the Catholic population in the United States.

    First, as indicated in the introduction of this work, survey statistics indicate that more than 75 million persons in the United States may identify themselves as Catholic. Yet a large proportion of this population rarely or never attends religious services. As earlier noted, the General Social Survey of the National Opinion Research Center for 2010 indicates that 25.2 percent of the population claims to be Catholic, but only 20.2 percent of the population claims both to be Catholic and to attend religious services at least once yearly, and that only 15.4 percent of the population claims both to be Catholic and to attend religious services more than once yearly. Multiplying these percentages by the U.S. population in 2010 of more than 308 million indicates that there are nearly 78 million Catholics in the United States, but only 62 million who attend religious services at least once yearly, and less than 48 million who attend more than once yearly. Put another way, the count presented in this work of persons known to parishes or missions, nearly 59 million, is reasonably close to the population of 62 million that both claims to be Catholic and to attend religious services at least once yearly.

    Second, The Official Catholic Directory (OCD) for 2010 indicated a Catholic (both Latin and Eastern) population of 65,836,730 in the 50 states and the District of Columbia. Yet there is reason to believe that the means used to generate the OCD number varies by diocese, with some dioceses relying on survey estimates of the Catholic population rather than parish-level statistics.

    Variations in reporting and accuracy by diocese were also evident in the data received for this work. We received attendance statistics for less than half of the churches. We received registration statistics and baptism and death statistics for most churches, but many did not provide all these statistics, while some provided more than we requested. Accuracy will very likely vary the amount of time and care each parish and diocese puts into gathering and reporting statistics-and the time and care appears to vary substantially.

    The adherent statistics as reported do reflect in most locations the number of Catholics calculated through a method developed by the Catholic Research Forum "based upon Canon Law and assum[ing] the definition of a Catholic as someone who is linked with the Catholic community through baptism and Catholic burial. The basis of the methodology is the computation of: 1) the percentage of babies born who receive Catholic baptism; 2) the percentage of people who die who receive Catholic funerals; and 3) an average of the baptism and funeral statistics." For more on this method, see Michael Cieslak, "Being Creative: Diverse Approaches to Estimating Catholics," paper presented to the annual meeting of the Religious Research Association, St. Louis, Missouri, October 1995. For more on varying methods for enumerating Catholic populations and their implications, see Clifford Grammich, "How Many Catholics? A Comparison of Methods for Estimating Catholic Populations," paper presented to the annual meeting of the Religious Research Association, Louisville, Kentucky, October 2008.