What you should know about this study

Data in this article are from the 1981, 1991 and 2001 Censuses of Population and from the 2002 Ethnic Diversity Survey (EDS). Interreligious unions refer to couples who at the time of the Census were married or living common-law with a partner from a different religious group. The Census asked respondents to report a specific religious denomination or group even if they were not practicing members of the group. People with no connection or affiliation with any religious group were asked to indicate that they had "No religion". "No religion" also includes atheists, agnostics, humanists, free thinkers and others who for whatever reason indicated that they were without a religious affiliation. This article refers to the following religious groups: Catholic, Protestant, Orthodox, Christian n.i.e. (not included elsewhere), Muslim, Buddhist, Hindu, Sikh, Other Eastern religions, "other religions" and "no religion". Marriages or common-law unions between denominations within a group (e.g. between a Roman Catholic and a Polish Catholic) are not counted as interreligious in this article whereas a union between two broad groups such as between a Protestant and a Buddhist is considered to be an interreligious union.

The Census records the current religion of respondents at the time of the Census. Current religion underestimates interreligious unions because a marriage or common-law union may lead to religious conversion of one of the partners. A religious conversion of a partner at the time of union formation is not collected by the Census.

Data from the 2002 was used to develop five logistic regression models (Quebec Catholics, Catholics outside Quebec, Protestants, "Other religions", "No religion") to estimate probabilities of a person in a couple being in an What you should know about this study CST interreligious union. The following variables were included in each model: gender , age, marital status, parents in an interreligious union when the respondent was aged 15, province of residence, religion of mother, religion of respondent, religiosity of respondent, highest level of schooling, home language and size of community where respondent lived in 2001. Predicted probabilities were calculated holding all variables at their mean value except the variable of interest.

The EDS surveyed the non-Aboriginal population aged 15 and over. About 42,500 people were interviewed of which 21,800 were in a conjugal union and were included in one of the logistic regression models.

Religiosity was measured using four dimensions - religious affiliation, attendance at religious services, personal religious practices, and importance of religion - in a simple additive scale. Individuals with no religious affiliation were assigned a score of 0, while those with an affiliation received a score of 1 to 13. People were grouped into three broad categories based on their religiosity index, low (0-5), moderate (6-10) and high (11-13). The group with 'low religiosity' includes persons with no religious affiliation.

This article uses the following terms:

Interreligious unions - couples where each partner is from a different religious group.

Homogamous unions - couples where partners are from the same religious group including unions between two people with no religion.

Co-religionists - people who are in the same broad religious group as the respondent