Underreporting or misreporting of demographic, social or economic characteristics associated with one of the sexes.
Additional notes and information
Some examples of sex bias in data collected are: underreporting of women’s economic activity; undercounting of girls, their births or their deaths; or underreporting of violence against women.
United Nations Statistics Division – UNSD. Glossary on Gender Statistics –
Global Gender Statistics Programme. Available at: http://unstats.un.org/unsd/genderstatmanual/Glossary.ashx