Labour Force Survey

Methodology

The sample for the LFS is drawn from the Land and Property Services Agency (LPSA) list. This is the most up-to-date listing of private households and is available to the Northern Ireland Statistics and Research Agency for research purposes. People living in institutions (although not in private households in such institutions) are excluded. 

A systematic random sample of 650 addresses is drawn each quarter from the LPSA list. The LPSA addresses are sorted by district council and ward, so the sample is effectively stratified geographically.

Every address selected for the LFS is interviewed on five successive occasions, so that in any one quarter, a fifth of the sample will be receiving their first interview, one fifth their second and so on, with one fifth receiving their fifth and final interview. This results in an 80% sample overlap between quarters.

First wave interviews are carried out by a team of interviewers who call at each address and attempt to obtain an interview. Where possible, subsequent interviews are carried out by a panel of telephone interviewers.

Questions are asked of every adult member of the household (aged 16 and over), with a few questions relating to each child in the household.