NorLAG Den norske studien av livsløp, aldring og generasjon

Data collection and sample

The Norwegian study on life course, ageing and generation (NorLAG)  provides knowledge about variation and life-course change by studying behaviour and transitions in four key domains: (1) Work and retirement, (2) Family and generations, (3) Mental health and quality of life, and (4) Health and care. Gender, cohort, and local communities are cross-cutting issues through all domains.

NorLAG is a longitudinal study with data collections every fifth year. So far, two waves of data have been collected. It uses a randomly selected sample drawn from 30 municipalities and townships from four regions of Norway. Municipality level data (mostly from public registers) are integrated with the individual-level survey data. The longitudinal design enables analysis of ageing and transitions as processes unfolding over time. NorLAG is initiated by NOVA. Statistics Norway has carried out all data collections.

Datasources

  • Telephone interview (CATI) (NorLAG1 and NorLAG2)
  • Postal questionnaire (NorLAG1 and NorLAG2)
  • Administrative register data: time series information on family, work, income, etc.

One study – multiple samples

The first wave (NorLAG 1) was conducted in 2002-03. The second wave (NorLAG 2) was conducted in 2007-08. The second wave is part of the nationally representative LOGG study (Life cOurse, Gender and Generation). The two waves and the combination of two studies give three analytical samples:

  • NorLAG 1-sample: 40-79 years
  • NorLAG 2-sample: 18+ years
  • NorLAG panel sample

NorLAG 1

The first wave of the data collection was conducted in 2002-03. It is based on a randomised and stratified sample of individuals aged 40+ years. The response rate for the telephone interview was 67 percent (N=5,589). Of these, 75 percent (N=4,169) responded subsequently to the postal questionnaire.

NorLAG 2

The second wave of data collection (NorLAG 2) was conducted in 2007-2008. The sample is drawn from the same NorLAG-municipalities and townships, but is extended to include also young adults (18-39 years). Thus, NorLAG 2 includes the whole adult life course (18-84 years). NorLAG 2 consists of 9,122 respondents (response rate is 59), of which  72 percent returned the postal questionnaire.

Read more about NorLAG2 (also termed LOGG) here.

NorLAG panel

Respondents who took part in both waves (2002-03 and 2007-08) constitute the NorLAG panel sample (N=3,796). In 2007-08, the sample includes the ages 45-84 years. A total of 289 persons dropped out between the waves, of which 264 individuals died and 25 moved abroad. Thus, 72 percent of those who responded to the first wave took part in the second wave. Compared to participants of the first wave, the panel sample is characterized by a somewhat higher educational level and better self-reported health. Attrition is also higher in older age groups. This pattern of selective attrition is found also in other panel surveys.

Easy-to-use panel data for NorLAG is available for research purposes via NSD. This datafile includes repondents aged 40-84 who took part in at least one of the two waves of data collection.

Funding

NorLAG and LOGG are financed by the Research Council of Norway (grant 149564 and 168373), the Ministry of health and Care Services, Ministry of Labour, Ministry of Children, Equality and Social Inclusion, Ministry of Local Government and Regional Development, NOVA and Statistics Norway.  NorLAG and LOGG are also part of ACCESS Life Course, which is financed by The National Financing Initiative for Research Infrastructure, financed by the Research Council of Norway (grant 195403) and NOVA.