Data and statistics

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. It is also needed for day-to-day decision making and enforcing the rules and laws.

In an age of shareable digital data, keeping sex records accurate and not confusing them with gender identity requires a government-wide solution with clear data standards.

What is the problem?

Over the past 15 years data collection on sex has been 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, and on personal identity documentation like passports and driving licenses.

In March 2025 The Sullivan Review of data, statistics and research on sex and gender was published. It set out in careful detail the grave problems with official data in areas including health, justice, education and the economy. I found that public data is in a mess. Many public bodies had stopped collecting data on sex, often replacing it with self-declared gender identity or a confused, undefined hybrid of gender identity and sex.

The problem relates not just to statistics, like the census, but also to personal data about people in areas such as healthcare and policing, where it is needed for decision-making.

Now the government is developing a new digital identity system that will allow apps and services to provide reusable, government-assured verification of their identity and facts about them, including the “fact” that people are male or female.

Whatever your position on mandatory or voluntary digital identification, one thing is certain: it only has one job to do. If any digital identity system is going to work, it must enable people to prove who they are, and prevent them from falsely proving that they are someone else. 

Sex Matters has been sounding the alarm about a flaw in the digital identity system since 2022: identifying individuals reliably is not compatible with allowing people to disappear from their old life in one sex and reappear with a new life and a new identity in the opposite sex. 

Digital identity verification can solve the problem of providing both accuracy and privacy, but only if the government establishes this as a clear policy goal.