The recommendations recently issued by the Conference of European Statisticians (CES) for the next round of population and housing censuses underline for the first time that some countries might find it in their interest to enumerate same-sex couples. Many pitfalls can be expected when such a sensitive topic is newly included in a census. The experience of the few western countries that have already taken initiatives in this direction helps identify difficulties to be faced and suggest "good practices" to be adopted. Coverage is extended to countries which rely on permanent registers rather than periodic censuses to enumerate their population.
Following the example of Denmark in 1989, a dozen western countries have introduced legal recognition for same-sex couples somewhat similar - and in a few cases equal - to marriage (Waaldijk, 2004). In parallel, there has been an increasing desire to know the numbers and characteristics of all same-sex couples. This has resulted in the use of traditional statistical sources to provide information on this relatively small group.
US demographers led the way with the 1990 census. Their experience was extended to more countries ten year later. For the 2010 round of population and housing censuses, the recommendations by the Conference of European Statisticians (CES) underline for the first time that some countries might find it in their interest to enumerate same-sex couples: "data needs can arise resulting from the increasing legal recognition of such unions, or on the importance of same-sex cohabiting partners who are not married/registered." (United Nations Economic Commission for Europe. Conference of European Statisticians, 2006, p. 107) The Conference suggests response categories that could be added to the household composition and/or to the de jure and de facto marital status questions to identify these couples. The CES has endorsed a plea by Statistics Canada, which proposed that "good practices" also be recommended, after reviewing the concepts and methods used in several countries (Statistics Canada, 2004). There are no such guidelines in the final document, despite the many pitfalls that can be expected when such a sensitive topic is newly included in a census. To begin to fill the gap we analyse the few cases of current practice. We also extend the coverage to countries which rely on permanent registers rather than periodic censuses to enumerate their population.
2. The 1990 and 2000 US censuses: issues at stake
The pioneering experience of US demographers, with the 1990 then the 2000 data, offers a good opportunity to examine the different problems associated with such an operation. The census is a huge statistical procedure to gather information from the whole population. It has many constraints, but it is nevertheless essential for collecting information on small groups, such as same-sex couples. This is particularly so if a breakdown of the geography and characteristics (sex, age, location, education, occupation or income) is wanted. Attempts to use survey data have severe limits due to sample size, even if a compilation is made of multiple waves of data collection.
The census uses a self-administered questionnaire, which cannot be too long nor too complicated. Moreover, given the official nature of the census, the various questions must have been agreed upon by a large number of public bodies as relevant for increasing our knowledge of the population2. Hence, the organisers of the census cannot develop a long set of questions to deal with a specific topic, especially if it is to identify and characterise a very small part of the population.
In the US, no specific question is addressed to same-sex couples and no specific response item is labelled so that such couples can identify themselves, and only themselves, through it. In fact, some sort of a two-step procedure is used: couples are identified first, then same-sex couples are identified because both members of the couple have given the same sex (two men or two women). …