The source of income is based on the main source of income in the month the survey is held. Data are drawn from the Social Statistical Database (SSB) and linked to the survey data. The various sources of income are: work as an employee or self-employed, benefits (disability, unemployment, social security and other benefits) and pensions.
A distinction is made between the category pupil/student and the category no source of income. The first category includes people attending some form of education; the latter includes people with no source of income from work, benefit or pension who do not attend any form of education.