Where sex matters | Data and statistics
Data and statistics
We need accurate data, disaggregated by sex in order to understand differences in the lives of women and men.

Sex is a powerful predictor of almost every dimension of social life including education, employment, crime, physical and mental health. It is difficult to think of an area of life where sex is not an important dimension for analysis.
As Caroline Criado Perez has pointed out, if data is not collected on men and on women then systems – from transportation to medicines and medical devices to tax structures and consumer products – tend to ignore the needs of women, and ”when your big data is corrupted by big silences, the truths you get are half-truths, at best.”
What is the problem?
Increasingly, accurate data collection on sex is being undermined by the conflation of sex, gender and gender identity.
The principle of self-ID has been accepted by many public bodies, replacing sex with self-identified gender when recording crimes and organisational pay gaps, on medical records and in the census.
All three of the UK census authorities (for England and Wales, Scotland and Northern Ireland) had said that they intended to carry guidance to accompany the sex question in the 2021 census that would instruct respondents to answer based on their self-declared gender identity, not on their natal sex or their GRC administrative sex.
Jonathan Portes, former chief economist at the Department for Work and Pensions, said that this would make it much more difficult to track and tackle issues such as the gender pay gap and inequality in childcare, social care, housing and health. There were also legal cases challenging the decision.
Updates
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Response to Victor Madrigal-Borloz’s report on the UK
The UN Independent Expert Victor Madrigal-Borloz has issued an extraordinary report at the end of his ten-day mission to the UK. The thrust of it is the familiar claim that speaking clearly about the material reality of the two sexes amounts to “hate”, alongside the equally familiar dismissal of...
12th May 2023
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Thank you, Kishwer Falkner
We have written to Baroness Kishwer Falkner, Chair of the Equality and Human Rights Commission: Dear Kishwer Falkner Thank you for publishing your letter to the Minister for Women and Equalities setting out, with careful reasoning, why you support revisiting and clarifying the meaning of “sex” as a protected...
11th April 2023
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EHRC publishes letter on clarifying sex in the Equality Act
Sex Matters’ press statement Sex Matters welcomes the letter from Kishwer Falkner, Chair of the Equality and Human Rights Commission, to Kemi Badenoch, the Minister for Women and Equalities, responding to her request for advice on clarifying the definition of the protected characteristic of sex in the Equality Act...
4th April 2023
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What did we learn from the census?
Key points The questions In 2021 the census for England and Wales included a voluntary question on gender identity for those aged 16 years and over. There was also a mandatory sex question which sought to collect information on people’s sex, which was clarified in court by Fair Play...
31st January 2023
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Sex Matters in the Media webinar
Helen Joyce of Sex Matters talked to communications consultant Conrad Roeber on Thursday 26th January at 7.30pm Watch the recording About the webinar Our director of advocacy, Helen Joyce, will be talking to communications consultant Conrad Roeber about the media’s failures in reporting on sex and gender, and what...
18th January 2023
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Risks in the final rush to legislate self-ID in Scotland
The Scottish government’s plans to allow anyone from age 16 upwards who is ordinarily resident in Scotland to obtain a gender recognition certificate (GRC) without any medical assessment are due to be voted on by the Scottish Parliament tomorrow, 21st December. The vote comes barely a week after the...
20th December 2022
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Clarify the Equality Act: sign the petition
The Equality Act 2010 protects everyone’s rights and covers everything from schools to hospitals, pubs to sports, and everybody’s workplace. It includes protection against sex-discrimination, and allows single-sex services. But on 13th December a judge in Scotland pronounced that Equality Act does not recognise biological sex as a protected...
16th December 2022
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Why we have written to UCAS about data
The latest attempt to destroy data on sex by replacing it with data on self-declared “gender identity” is in the higher-education system. The Universities and Colleges Admissions Service (UCAS), the national undergraduate admissions service that acts as gatekeeper to all university places, is planning to change an already-flawed question...
7th December 2022
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Campaign update: Day 1
Yesterday we launched the Make the Equality Act Clear petition, calling on the government to clarify, with a legislative amendment, that sex means sex in the Equality Act 2010. It got an amazing response. In less than 24 hours, 15,000 people signed the petition, and the number is continuing...
3rd November 2022
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Sex Matters’ advice to companies on the FCA’s new reporting requirements
Last week, we reported that the Financial Conduct Authority had issued new rules about its requirements for listed companies to report on the proportion of women on corporate boards, scrapping its earlier proposal for this to be based purely on gender self-identification. The new regulations let companies choose whether to report...
29th April 2022
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Financial Conduct Authority says corporate boards can use sex not gender
The Financial Conduct Authority has issued new rules requiring listed companies to report on the proportion of women on corporate boards, scrapping its earlier proposal to require this to be based on gender self-identification. 439 people and organisations (over 80% of respondents) raised the issue of gender vs sex...
20th April 2022
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Sex in the Census: Reality v Paperwork
The Outer House of the Court of Session in Scotland handed down judgment last week in Fair Play For Women’s challenge to guidance on the census. National Records Scotland plans to tell members of the public that if they are transgender, they can choose how to answer the sex question. ...
22nd February 2022
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A radically simpler system than gender self-ID
Critics of the Gender Recognition Act who call for gender self-identification say the current system is too much of an administrative burden. They are calling on the government to bring people together to find solutions.
21st February 2022
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Do crime victims deserve respect?
We think crime victims deserve respect, dignity, sensitivity, compassion and courtesy, as specified in the Victims’ Code.
10th February 2022
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X passports appeal dismissed
The Supreme Court has unanimously dismissed Christie Elan-Cane’s case for an “X” passport. The judgment states “There is no judgment of the European Court of Human Rights which establishes a positive obligation to recognise a gender category other than male or female, and none which would require the Secretary...
15th December 2021
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No need for sex data on domestic abuse?
Yesterday the Domestic Abuse Commissioner launched a survey for survivors of domestic abuse about their experience of using domestic abuse services across England and Wales: “We are running this survey so that we can understand what is good about domestic abuse services in different areas of the country, and...
7th December 2021
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Sex matters in the City
The Financial Conduct Authority is the regulator for the financial services sector in the UK. They are proposing to set new rules to encourage big companies to have more “female” directors on their boards. The new regulations would cover over 1000 firms, employing tens of millions of people, and...
19th October 2021
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Fighting for the principle of collecting data on biological sex
A guest post by MurrayBlackburnMackenzie. Scottish Parliament Public Petition: Call for signatures In early June MurrayBlackburnMackenzie (MBM) lodged a petition with the Scottish Parliament Public Petitions Committee. It calls on the Scottish government to require Police Scotland to accurately record the sex of people charged or convicted of rape...
27th June 2021
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Truth and reconciliation
How should the public sector leave the Stonewall Champions Scheme?
6th June 2021
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Time to #LeaveStonewall
This is the letter we have sent to the CEOs of the 850 organisations that are members of the Stonewall Diversity Champions Scheme. Re: Leaving the Stonewall Diversity Champions Scheme We are writing to call on you to withdraw from the scheme, both for the sake of your own...
29th May 2021
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Sex, gender and medical data: a way forward
Susan Bewley, Margaret McCartney, Catherine Meads and Amy Rogers published an article in the British Medical Journal calling for clarity about sex and gender in medical records and data.
This a "rapid response" from Sex Matters co-founder Maya Forstater that was published online by the BMJ.23rd March 2021
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NHS: let’s talk about sex
This tweet by Emma Parnell, Lead Service Designer at NHS Digital and the associated Medium post “Lets Talk About Sex” is interesting. Parnell writes in detail about how she worked to remove the question of whether a patient is male or female from the online system for booking COVID...
20th March 2021
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Sex (or gender?) as a hate crime: why the rush?
The push to adopt a gender neutral definition of “misogyny” as a hate crime with amendment 87B to the Domestic Abuse Bill (being debated this afternoon in the House of Lords) is another attempt at the political erasure of sex. Why the rush when the Law Commission is working...
17th March 2021
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Census guidance on the sex question ruled unlawful
Census day is 21 March 2021. Yesterday, in a challenge brought by Fair Play For Women, the High Court ordered the Office for National Statistics to correct the guidance they provide online about how to answer the question “What is your sex?” Until yesterday, the guidance for the 2021...
10th March 2021
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ONS reverses decision to ask clear sex question on the census
The ONS has reversed its decision not to allow self-identified answers to the sex question in next month’s Census. On 22 January, 2021 The UK’s Chief Statistician, Professor Ian Diamond, confirmed on BBC Radio 4’s Today program the question “what is your sex” should be answered according to someone’s LEGAL SEX,...
12th February 2021
Other resources
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‘Nonsense’ of gender data collected by public bodies set for review
Ben Riley-SMith, political editor for The Telegraph
The Tories are hardening their position on the importance of biological sex being recognised amid the debate about transgender rights. -
Census ‘hugely overstated’ trans population
Edward Malnick, Sunday Political Editor for The Telegraph
Office for National Statistics may have lost its 'credibility' to accurately record sex and gender, suggests Whitehall source -
Parkrun ‘self-ID’ lets biological male runners ‘smash women’s records’, Olympian claims
Catherine Lough for The Telegraph
An article prompted by what Mara Yamauchi, a member of Sex Matters' advisory group, has written. -
EDI contra science – the misuse of “ethics” in academic research
John Armstrong writes for The Crtitic about how he was asked to survey elite athletes on their views on trans participation in athletics, but the ethics committee at King’s College, London rejected his research proposal on the grounds that the terms “male” and “female” were unacceptable.
1st April 2023
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Fair Play For Women
Campaigning and consultancy group which raises awareness, provides evidence and analysis, and supports policy-makers to protect the rights of women and girls in the UK. Opposes sex self-ID, and also played a large part in the government’s decision to abandon plans to introduce it in England and Wales in...
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Why does the census say there are more trans people in Newham than Brighton?
Sex Matters board member Michael Biggs writes in The Spectator about the confusion caused by unclear language about sex and gender in the 2022 census.
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Gender Identity in the 2021 Census of England and Wales: What Went Wrong?
By Michael Biggs.
The 2021 Census of England and Wales was the first in the world to elicit information on gender identity from an entire population. This paper argues that its results are implausible on the dimensions of geography, education, ethnicity, and religion. -
DBS checks and identity verification: safeguarding loopholes created by changes of identity
An analysis by Keep Prisons Single Sex of the exceptional privacy rights given to those who change their gender as well as their identity.
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How police forces in England and Wales record suspects’ sex in crime and incident reporting
Keep Prisons Single Sex reports that from its research it is clear that many police forces record suspects’ gender identity in lieu of sex registered at birth, frequently on the basis of self-identification.
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Effective communication about pregnancy, birth, lactation, breastfeeding and newborn care: the importance of sexed language
Karleen D. Gribble, Melissa C. Bartick, Roger Mathisen, Shawn Walker, Jennifer Gamble, Nils J. Bergmann, Arun Gupta, Susan Bewley, Jennifer J. Hocking and Hannah G. Dahlen in Frontiers
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Passports must show M or F for sex
An appeal was made to the Supreme Court after the Court of Appeal had concluded that an applicant for a passport must declare their gender/sex as being either male or female, not “unspecified” (“X”).
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Stats for gender
Genspect, an organisation which supports parents with gender-questioning kids, created this website because it believes that the public has a right to reliable data, intuitively categorised, and phrased in simple, jargon-free terms, and wants those who are questioning their gender to have full access to the facts.
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Legal Feminist responds to FCA consultations
Legal Feminist applauds the intention behind the proposals, and is a strong proponent of data-driven policy-making, but felt that the way in which those intentions were to be reflected in rules and policy rendered the proposals at best ineffective and at worst dangerous.
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Sex and the Office for National Statistics: a case study in policy capture
How did the ONS end up in court defending its guidance on a question which most people would deem self-explanatory? Alice Sullivan explains the legislative and political context around gender recognition, and the consequences for data collection.
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Gender markers in passports: internal review of existing arrangements and possible future options
Report by HM Passport Office, 2014
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Swedish cohort study on sex reassignment
Long-Term Follow-Up of Transsexual Persons Undergoing Sex Reassignment Surgery: Cohort Study in SwedenDhejne C, Lichtenstein P, Boman M, Johansson ALV, Långström N, et al. (2011) Long-Term Follow-Up of Transsexual Persons Undergoing Sex Reassignment Surgery: Cohort Study in Sweden. PLOS ONE 6(2): e16885.
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Women count, count women: webinar
Keeping the category of sex mandatory and clear in the census was a campaigning priority of Woman’s Place UK from 2017. In October 2020 they hosted a webinar on the census with Alice Sullivan, Lisa Mackenzie, Jane Clare Jones and Selina Todd.
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Open letter on the census
On December 15 2019, 80 of the UK’s leading social scientists wrote an open letter, which was published in the Times, listing their concerns about letting census respondents list their self-identified gender.
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The political erasure of sex
Jane Clare Jones with Lucy MacKenzie (2020), Oxford University The first in a series, this report ‘Sex and the Census’ focuses on planned changes to the way that data on sex is collected in the UK census and outlines why collecting census data on males and females matters.
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Murray Blackburn Mackenzie
MurrayBlackburnMackenzie is an independent policy analysis collective. Its work on proposals for the 2021 UK census and related research has been cited in the Scottish Parliament and informed parliamentary questions and debate.
Publications
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Freedom of belief matters
Sex Matters’ response to a call for input by the United Nations’ Independent Expert on protection against violence and discrimination based on sexual orientation and gender identity.
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Groups defending sex-based rights
Overview of groups opposing sex self-ID in the UK, set up by individuals and collectives concerned by the failure of established third-sector organisations to defend women’s sex-based rights, child safeguarding and evidence-based policymaking. Also listed on our website.
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Diversity and inclusion on boards: advice to companies on new FCA reporting requirements
The Financial Conduct Authority has left it up to companies to determine how they define “men” and “women” in their diversity reporting. This briefing aims to assist boards in complying with the new regulations. We recommend the simplest, clearest, most neutral and most coherent approach: reporting based on sex.
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Sex and digital identities
How digital identities can solve the problem with sex and gender identity – and how getting it wrong will make the problem worse.
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Getting it right – diversity and inclusion on company boards and executive committees
The Financial Conduct Authority’s proposal for monitoring diversity and inclusion is well intentioned, but flawed. Sex Matters and Legal Feminist outline the practical and legal problems in abandoning sex-based monitoring for the controversial concept of “gender identity”, and suggest a better solution.
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Sex Matters response to Financial Conduct Authority consultation
Why the listing rules for diversity and inclusion should follow the law.
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Gender Recognition Act reform – evidence submission
We answer the Women and Equalities Select Committee‘s questions and make six recommendations.