An excellent article in today's @spectator by @ProfAliceS about the importance of sex-disaggregated data and concern that more and more organisations are failing to collect data on sex or conflating or replacing it with data on gender identity: https://www.spectator.co.uk/article/Coronavirus-shows-why-its-vital-to-distinguish-sex-and-gender

Professor Sullivan refers to guidance proposed to accompany the sex question in the 2021 census that will instruct respondents to answer based on their self-declared gender identity. https://murrayblackburnmackenzie.org/2019/12/10/draft-guidance-under-consideration-for-2021-census-sex-question-summary-of-proposals/

In December 2019, 80 eminent UK social scientists wrote to the three UK census authorities expressing concern about this guidance, particularly its potential impact on population sub-groups. https://www.parliament.scot/S5_European/General%20Documents/CTEEA_2019.12.18_Sullivan.pdf