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Sex and gender

Policy details

Metadata item Details
Publication date:4 September 2019
Author:Eliza Swinn
Approver:Catherine Davies
Who this is for:Users and producers of statistics
Type:Harmonisation guidance and principles

This page provides information on work underway across the Government Statistical Service to harmonise measures of sex and gender in data collection across government.

The update below focuses on the harmonisation of sex questions in the UK censuses (England & Wales, Scotland and Northern Ireland). Some information is provided in the ‘related work’ section on harmonisation of gender questions, as well as the development of harmonised standards for collecting sex and gender data in surveys and administrative data collections. This work is ongoing, and further information will be provided in due course.

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Measuring sex in the UK censuses: Harmonisation update

5th September 2019

The census teams at the Office for National Statistics (ONS, who carry out the census in England and Wales), National Records of Scotland (NRS) and the Northern Ireland Statistics and Research Agency (NISRA) have been working closely together throughout development of the 2021 census questionnaires to share research and work towards harmonisation where possible.

The Government Statistical Service (GSS) Harmonisation Team works across the UK to promote and facilitate harmonisation.

A meeting between the GSS Harmonisation Team, ONS, NRS, NISRA and Welsh Government was held on 8th August 2019 to review work to date and proposed questions, and identify any further research needs. This meeting covered the proposed census sex and gender identity/trans status questions. The update below provides information on the harmonisation of the sex question, which is a priority due to the importance of this data. This work is ongoing and so further information on the gender/trans status questions will be provided in due course.


The importance of harmonising sex questions in the UK censuses

Harmonisation is about making statistics and data more comparable, consistent and coherent.

Statistics are developed to meet specific needs. They make use of an extraordinarily varied range of data, which are increasingly gathered for non-statistical purposes. Because of this, different statistics will often measure similar concepts using different definitions and classifications. When considering each set of statistics in isolation, this approach is satisfactory. When considering how they fit together into a wider evidence base we can do more to ensure they are comparable by using consistent definitions, language and question structure in data collection and statistics production, where this is appropriate and beneficial.

The need for harmonisation is particularly important when considering key demographic variables – with sex (and age) being the most prominent of these. This is because sex is taken into account in a huge proportion of the analysis that goes on across government, as well as in academia and other spheres. In many cases this will be in examining any differences in results by sex, while in other cases sex is used as a weighting variable (to allow more accurate comparisons between different groups to be made). Data on sex is of key importance for equality monitoring.

The sex data collected in the UK censuses is of particular importance, as much other data analysis is adjusted to match the proportions of the sexes found in the census. This is important data for understanding population dynamics and projecting future change.


Current proposed sex questions for the 2021 UK censuses

Under current proposals, the data gathered on sex in the three censuses will be harmonised across the UK. Information about the proposed questions is provided below. The questions are subject to parliamentary approval and some research is still ongoing in Scotland.

  • The 2011 and proposed 2021 sex questions ask: ‘What is your sex?’, with the response options ‘Female’ and ‘Male’. This question on sex has been asked on the censuses for many decades and the consistency of this is unchanged, which is vital for identifying trends over time.
  • For some respondents, in particular those who do not live as the sex they were registered at birth, this can be a difficult question to answer, not least because there is a need to maintain privacy. This means that those who seek guidance in answering the question will be advised that it does not need to be the same as their birth certificate.
  • ONS, NRS and NISRA have engaged widely on the 2021 Census and thoroughly tested their proposals to ensure high quality and consistent data.
  • Guidance has been shared with stakeholders and tested with the public to ensure it is clear and well understood.
  • In Scotland different versions of the guidance have been shared with stakeholders and are being tested to see how they affect the data and response rates.


Key timings for publication of plans and research on UK census sex questions

Approximate timescales for future work on the agreement and harmonisation of sex questions for the UK censuses are detailed below. As questions are subject to parliamentary approval, these timings may change.

  • From Late 2019 to Early 2020 – ONS publication of a series of question development reports detailing the proposed questions and the research on measuring sex, gender and sexual orientation.
  • Late 2019/Early 2020 – Census legislation for England and Wales, Scotland, and Northern Ireland laid before respective parliaments/assemblies, including proposed questions.
  • Late Spring 2020 – a report will be published on the harmonisation of UK census sex (and gender) questions.

Related work

A number of related strands of work are underway across the UK, and some information on key projects is provided below. The teams working on all these projects are communicating regularly with one another to share research and coordinate where possible.

  • UK census gender question development

Census questions are being developed by the ONS and NRS to measure gender identity/trans status. NISRA do not currently plan to ask a question on this topic, however they have included a gender identity question in their Continuous Household Survey. The national statistics agencies and GSS Harmonisation Team have been liaising to share research and explore harmonisation of this data. Further information will be published on this topic in due course.

  • Cross-government gender identity, sex and sexual orientation harmonisation work and the Government Equalities Office LGBT Action Plan commitments

A programme of work is underway to develop harmonised sex and gender question standards for use in government surveys and administrative data collections.

As part of this, ONS and the GSS Harmonisation Team are working with the Government Equalities Office (GEO) to address two of the commitments made in the LGBT Action Plan. These commitments involve development of monitoring standards for sexual orientation and gender identity across central government and providing guidance and support towards their implementation. Additionally, ONS and GEO are working with Civil Service HR to develop standardised questions on sexual orientation and gender identity for inclusion in internal departmental systems. Further information on these commitments can be found in the LGBT Action Plan.

A large amount of research and stakeholder engagement has already been undertaken on these topics, and a cross-government workshop is being held later in September 2019 to further understand needs and prioritise requirements. Information on next steps will be published following this workshop.

  • Scottish Government working group on sex, gender and data

The Scottish Government are establishing a working group on sex, gender and data. Its membership will comprise of professionals from across statistical services and will be led by and report to the Chief Statistician. The group will consider the guidance that should be offered to public bodies on the collection of data on sex and gender, including what form of data collection and disaggregation is most appropriate in different circumstances.

  • NHS England Unified Information Standard for Protected Characteristics Scoping Project

NHS England are currently carrying out an equality monitoring scoping project to assess the need for a unified information standard for the nine characteristics protected under the Equalities Act. These include sex, gender reassignment, and sexual orientation. The Office for National Statistics (ONS) is a member of the Steering Group for the project and aims to ensure that the approach being developed takes account of developments across Government.


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