Census (Amendment) (Scotland) Bill: MBM Stage 3 Briefing

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The main purpose of the Census (Amendment) (Scotland) Bill is to introduce two new, voluntary questions on sexual orientation and transgender identity/status. These changes are not controversial and were agreed at Stage 2.

The Scottish Government also wishes to change the sex question, to capture both sex and gender identity in a single question.

Options currently under consideration by NRS include a non-binary sex question (male/female and a third response option) and a binary sex question, with separate guidance stating that a person may respond in their self-identified sex. This briefing looks at the principle of combining sex and gender-identity in a single ‘sex’ question.

1. Data integrity and quality

The proposed introduction of self-identification to the sex question conflates sex and gender identity, which are 2 separate concepts. Gender identity is based on subjective feelings, and is not defined in law. Sex is officially recorded at birth and based on observed physical characteristics. Sex is also a protected characteristic under Section 11 of the Equality Act 2010, and defined as biological (although possession of a Gender Recognition Certificate allows a person to change their sex for most legal purposes).

While all census question responses are self-declared and not checked for accuracy, there is a substantive difference between responding to the sex question without any direction or guidance, and responding in a context where formal guidance states that sex has no definition beyond the respondent’s self-assessment.

A self-identified sex question carries risks in terms of data quality. Data collection should be based on clear measurable criteria. Including sex and gender identity in the same question means that it will not be possible to determine what the data represents. There is no way of knowing how this will affect data quality, because the size of the transgender population is currently not known, and if the question is asked this way how many declared a sex different from that on their birth certificate will be unknowable. This is not consistent with the purpose of the census as a data-collection exercise.

It is not possible to predict how the proposed change to the sex question will impact on overall data quality, particularly given that we appear to be in a period of social change in relation to gender identity (as indicated by increasing referrals to Gender Identity services). These risks will be higher among sub-populations, most obviously younger age groups.

The 2021 census will also set a precedent for other data-gathering exercises and surveys. Scottish Government policy already prioritises gender over sex for policy-making purposes, and it is likely that a self-identification sex question would cement this shift, resulting in the eventual loss of robust data on the protected characteristic of sex more widely.

2. Losing sight of women’s interests

If a self-identification ‘sex’ question is formally introduced in the 2021 census (via forthcoming secondary legislation) it will show that the legislature no longer considers that robust data on the number of males and females in the population is needed, as a matter of principle. This is a very different position to the 2011 census, where self-identification was introduced without due process or any form of democratic oversight (see below).

The proposed introduction of a self-identified sex questions places no value on the protected characteristic of sex, or the implications of losing data on sex for policy. Given the persistence of sex-based discrimination, it is not clear why the Scottish Government believes that robust data on sex is no longer relevant for planning purposes, equalities monitoring (as required under the Equality Act 2010) or understanding how society works.

Despite significant implications for legal and policy interpretations of sex, the formative period of policy development on the sex and gender identity questions in the 2021 census was directed towards a specific set of interests that excluded those of women.

The Equality Impact Assessment (EQIA) on the Bill makes no conclusion about the potential impact on the quality of data collected on the protected characteristic of ‘sex’. It grouped the two separate protected characteristics of ‘sex’ and ‘gender reassignment’ together, and does not comment substantively on the first.

A self-identified sex question risks setting a legal precedent that will challenge the basis of the Equality Act 2010. If it is accepted that it is wrong in principle to ask about a person’s legal or biological sex, the operation of the Act is likely to become unworkable insofar as it will set a precedent that disallows data collection in relation to the protected characteristic of ‘sex’.

3. Self-identification guidance in 2001 and 2011

At Stage 1 it was stated that both the 2001 and 2011 censuses collected data on self-identified sex. Mr Tim Hopkins, Director of the Equality Network stated: “In 2011 the 1% of people who are trans were told to answer it according to the sex that they believed themselves to be. In fact, the Office for National Statistics issued guidance for the England and Wales census for 2001 that said the same thing, so this has been going on for two decades” (col. 25).

In 2001 it appears a letter was sent from the ONS, in response to a member of campaign group ‘Press for Change’, which stated that that person could answer the sex question in line with their self-identified sex. Press for Change then placed this on its website. While the letter was viewed as marking a change in the ONS position by Press for Change, there is no publicly available evidence to support the broader claim that people were told to answer in terms of their lived sex.

In 2011, both ONS and NRS published online guidance advising those who regarded themselves to be ‘transsexual’ or ‘transgender’ to ‘select the option for the sex that you identify yourself’, irrespective of birth certificate details or the possession of a Gender Recognition Certificate.

The introduction of guidance in 2011 was recommended in an assessment undertaken by an independent consultancy, which erroneously stated that ‘sex includes gender reassignment’ and wrongly advised that ONS was under a statutory duty to issue guidance reflecting this. There was no parliamentary oversight of this move, or public discussion or consultation beforehand.

It is impossible to know if and how these changes impacted on data quality. It is not known how widely the written advice on the 2001 census was shared. The 2011 guidance was not on the face of the census form, and it is not known how widely this was known about or adhered to.  

This means that for an unknown and unknowable group of people it will never be clear what type of data on sex was collected. As such, it is questionable whether the sex data in the 2011 census is fit for purpose. At Stage One Professor Susan McVie (2018: col. 4) stated:

I think that the General Register Office for Scotland got it wrong when it redesigned the census in 2011 and conflated sex and gender identity into one question. We are now trying to disentangle those things. Arguably, the measure of sex in the 2011 census data is not accurate.


Given the risks to data quality, future data gathering exercises, equalities monitoring and women’s interests more widely, if formal guidance states that sex has no definition beyond the respondent’s self-assessment this will not be consistent with the purpose of the census, and should not be repeated in 2021.

The most pragmatic and appropriate approach in 2021 is to recognise that both sex and self-declared gender identity may be relevant to people’s lives, and to ask questions about each one separately. The more data we gather on both characteristics, the better placed we will be to understand the operation of each one individually, and together.