The criteria used to place a person into the classification are the biological characteristics of that person.
Sex is a flat classification with two categories:
1 Male 2 Female
No provision is made for residual categories as, in line with international practice, it is Statistics New Zealand policy to impute missing values for sex data.
The full classification is available in the 'Available files' section on the main page.
Imputation: Where the response for the sex variable is not a single response, or if the sex variable is missing, a value of male or female should be imputed. If available, information such as the name of the person or their relationship to others in the household may be used to impute a value. Indeterminate sex: In some circumstances, particularly administrative collections dealing with perinatal data, a third category may be required for individuals whose biological sex cannot be determined as male or female. They should be classified as being of ‘indeterminate’ sex. Where the collection uses numeric codes, the code '3' should be used. Some existing classifications use alpha codes. The collection of indeterminate sex is currently limited to administrative settings where sex is verified as part of the data collection process. Sample or self-administered surveys will generally only require, and only be able to collect, male and female. Within Statistics NZ the indeterminate sex category is applicable in processing of the birth registrations data used in the derivation of vital statistics. For statistical reporting purposes, sex will be imputed in those rare cases where it is recorded as indeterminate. For collections which require a classification including indeterminate sex, the suggested classification for use with numeric codes is:
1 Male 2 Female 3 Indeterminate In the limited range of data collections that include a third category for indeterminate sex (eg perinatal collections) it may also be useful to have an output category for indeterminate sex.