From 2001 the National Statistics Socio-economic Classification (NS-SEC) is being used for all official statistics and surveys. It replaces Social Class based on occupation and Socio-economic Groups (SEG).

This change has been agreed by the National Statistician following a major review of government social classifications commissioned in 1994 by the Office of Population Censuses and Surveys (now the Office for National Statistics) and carried out by the Economic and Social Research Council

NS-SEC is an occupationally based classification but has rules to provide coverage of the whole adult population. The information required to create NS-SEC is occupation coded to the unit groups (OUG) of the Standard Occupational Classification 2000 (SOC2000) and details of employment status (whether an employer, self-employed or employee; whether a supervisor; number of employees at the workplace). Similar information was previously required for Social Class and SEG. The full classification comprises 17 classes. There are three harmonised reduced versions, with eight, five and three classes (for the eight class version, the first class can be subdivided). A major change from SEG is that there is no longer a manual/non-maunal split. See Appendix E for more details.

The report presents the new categories of NS-SEC in all tables where previously SEG was used. In general we have used the eight category version and where tables were previously presented for the manual /non-manual groups we have used the three category version of NS-SEC. This clearly is not appropriate for the time series tables. Figures for the current year data are presented classified by NS-SEC. A supplement will be published soon after the completion of this report containing analyses investigating the effect of this change on time series data. This supplement will focus on smoking and drinking for which the GHS is an important source of socio-economic time series data.