Methodology

The analysis in this report is based on Pew Research Center surveys conducted between 2007 and 2021, including:

The 2021 National Public Opinion Reference Survey (NPORS), conducted online and by mail among a nationally representative group of respondents recruited using address-based sampling (ABS). The survey was conducted among 3,937 respondents from May 29 to Aug. 25, 2021. The response rate was 29%. Complete details about how the 2021 survey was conducted are available here.

The 2020 NPORS, conducted online and by mail among a nationally representative group of respondents recruited using ABS. The survey was conducted among 4,108 respondents from June 1 to Aug. 11, 2020. The response rate was 29%. Complete details about how the 2020 survey was conducted are available here.

The 2014 Religious Landscape Study (RLS), conducted by telephone (cellphones and landlines) among a nationally representative group of respondents recruited via random-digit dialing (RDD). The survey was conducted among 35,071 respondents from June 4 to Sept. 30, 2014. The response rate was 11% for the landline sample and 10% for the cellphone sample. Complete details about how the 2014 survey was conducted are available here.

The 2007 RLS, conducted by landline telephone among a nationally representative group of respondents recruited via RDD. The survey was conducted among 35,556 respondents from May 8 to Aug. 13, 2007. The response rate was 24%. Complete details about how the 2007 survey was conducted are available here.

Estimates for 2008-2013 and 2015-2019 come from other Pew Research Center RDD telephone surveys. Data on the country’s religious composition come from multiple political surveys conducted each year and then aggregated to produce yearly estimates. The questions on prayer frequency and religion’s importance in people’s lives were asked less often in the Center’s RDD surveys, and those estimates are based on one or two surveys (if any) conducted in a given year, as indicated in the table below. Today, almost all of the Center’s U.S. polling is conducted online rather than by telephone, but additional information on how the Center conducted RDD surveys is available here.

Sample sizes and margins of error

The following table shows the unweighted sample sizes and the error attributable to sampling that would be expected at the 95% level of confidence for estimates included in this report. In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.

Question wording

The questions used in this analysis are as follows:

NPORS

ASK ALL:

RELIG   What is your present religion, if any?²

1         Protestant (for example, Baptist, Methodist, Non-denominational, Lutheran, Presbyterian, Pentecostal, Episcopalian, Reformed, Church of Christ, etc.)
2         Roman Catholic
3          Mormon (Church of Jesus Christ of Latter-day Saints or LDS)
4          Orthodox (such as Greek, Russian, or some other Orthodox church)
5          Jewish
6          Muslim
7          Buddhist
8          Hindu
9          Atheist
10        Agnostic
11        Something else (SPECIFY)
12        Nothing in particular

 

ASK IF SOMETHING ELSE OR NO RESPONSE TO RELIG (RELIG = 11 OR REFUSED):

CHR      Do you think of yourself as a Christian?³

1          Yes
2          No

 

ASK IF CHRISTIAN (RELIG=1-4 OR CHR=1):

BORN   Would you describe yourself as a “born-again” or evangelical Christian?⁴

1          Yes, born-again or evangelical Christian
2          No, not born-again or evangelical Christian

 

ASK ALL:

ATTEND            Aside from weddings and funerals, how often do you attend religious services?

1          More than once a week
2          Once a week
3          Once or twice a month
4          A few times a year
5          Seldom
6          Never

 

ASK ALL:

RELIMP             How important is religion in your life?

1          Very important
2          Somewhat important
3          Not too important
4          Not at all important

 

ASK ALL:

PRAY                Outside of attending religious services, how often do you pray?

1          Several times a day
2          Once a day
3          A few times a week
4          Once a week
5          A few times a month
6          Seldom
7          Never

RDD telephone surveys (including the 2007 and 2014 RLS)

 

ASK ALL:

RELIG               What is your present religion, if any? Are you Protestant, Roman Catholic, Mormon, Orthodox such as Greek or Russian Orthodox, Jewish, Muslim, Buddhist, Hindu, atheist, agnostic, something else, or nothing in particular?

INTERVIEWER: IF R VOLUNTEERS “nothing in particular, none, no religion, etc.” BEFORE REACHING END OF LIST, PROMPT WITH: and would you say that’s atheist, agnostic, or just nothing in particular?]

1          Protestant (Baptist, Methodist, Non-denominational, Lutheran, Presbyterian, Pentecostal, Episcopalian, Reformed, Church of Christ, Jehovah’s Witness, etc.)
2          Roman Catholic (Catholic)
3          Mormon (Church of Jesus Christ of Latter-day Saints/LDS)
4          Orthodox (Greek, Russian, or some other orthodox church)
5          Jewish (Judaism)
6          Muslim (Islam)
7          Buddhist
8          Hindu
9          Atheist (do not believe in God)
10        Agnostic (not sure if there is a God)
11        Something else (SPECIFY)
12        Nothing in particular
13        Christian (VOL.)
14        Unitarian (Universalist) (VOL.)
99        Don’t Know/Refused (VOL.)

 

ASK IF SOMETHING ELSE OR DK/REF (RELIG = 11, 99):

CHR                  Do you think of yourself as a Christian or not? [IF R NAMED A NON-CHRISTIAN RELIGION IN PREVIOUS QUESTION (e.g. Native American, Wiccan, Pagan, etc.), DO NOT READ (ENTER “NO” CODE 2)]

1          Yes
2          No
9          Don’t know/Refused (VOL.)

 

ASK IF CHRISTIAN (RELIG=1-4, 13, OR CHR=1):

BORN               Would you describe yourself as a “born-again” or evangelical Christian, or not?

1          Yes, would
2          No, would not
9          Don’t Know/Refused (VOL.)

 

ASK ALL:

ATTEND            Aside from weddings and funerals, how often do you attend religious services… more than once a week, once a week, once or twice a month, a few times a year, seldom, or never?

1          More than once a week
2          Once a week
3          Once or twice a month
4          A few times a year
5          Seldom
6          Never
9          Don’t know/Refused (VOL.)

 

ASK ALL:

RELIMP             How important is religion in your life – very important, somewhat important, not too important, or not at all important?

1          Very important
2          Somewhat important
3          Not too important
4          Not at all important
9          Don’t know/Refused (VOL.)

 

ASK ALL:

PRAY                People practice their religion in different ways. Outside of attending religious services, do you pray several times a day, once a day, a few times a week, once a week, a few times a month, seldom, or never?

1          Several times a day
2          Once a day
3          A few times a week
4          Once a week
5          A few times a month
6          Seldom
7          Never
9          Don’t know/refused (VOL)