4. Conclusion

4.1 As this interim report makes clear, there was always good reason to expect a significant degree of uncertainty around estimates of the transgender population derived from the gender identity question in the 2021 Census, given that this is the first time that the question has been asked, that the concept of gender identity may be unfamiliar to many people, that the proportion of the population who are trans is relatively small and that there are few robust alternative sources of data to cross-check against.

4.2 ONS has engaged to develop, test and quality assure a question and data on gender identity to meet user need. While there are lessons to learn, ONS made decisions with the right motivations and in line with the Code of Practice for Statistics.

4.3 However, ONS should have communicated the inherent uncertainties in this new data collection when it published the data to aid use. Had ONS done so, it would have aided users understanding of appropriate use of the data and provided relevant context when issues were identified by users. ONS could have been more open and transparent about these novel data and the work that has followed.

4.4 A willingness on the part of ONS to provide further context and clarity on the initial estimates would be evidence of the strength of the Census process and not a weakness. ONS providing updates to the interpretation of these estimates should be regarded as a normal part of ongoing statistical production for a new area of data collection. The same would be true of any changes to the initial estimates, as long as they are fully and transparently explained. Such updates should not undermine user confidence in the robustness of the Census results as a whole, in which most questions have been asked many times before.

4.5 We are satisfied that the overall approach to the 2021 Census complies with the standards of trustworthiness, quality and value in the Code of Practice for Statistics in order to achieve ‘accredited official statistics’ status, but we will consider the accreditation of this subset of the Census dataset when ONS publishes its research findings. We will publish a follow up report with our findings after we have reviewed, and engaged with users on, the full set of research.