About the statistics
Name and topic
Name: Labour force survey
Topic: Labour market and earnings
Division for Labour Market and Wage Statistics
Definitions of the main concepts and variables
Concepts and definitions are in accordance with recommendations given by the International Labour Organization (ILO) and EU/Eurostat.
According to the international recommendations persons above a specified age should be classified by their attachment to the labour market in a specified, short period, either a day or a week. In the Norwegian LFS the reference period is one week, and the sample of persons are classified in relation to their situation in that reference week.
Employed persons are persons aged 15-74 who performed work for pay or profit for at least one hour in the reference week, or who were temporarily absent from work because of illness, holidays etc. Conscripts are classified as employed persons. Persons engaged by government measures to promote employment are also included if they receive wages. Persons laid off 100 per cent with a continuous duration of until three months are defined as employed, temporarily absent.
Unemployed persons are persons who were not employed in the reference week, but who had been seeking work during the preceding four weeks, and were available for work in the reference week or within the next two weeks (in 1996-2005 one should be available within two weeks following the time of interview, and until 1996 one should be able to start working in the reference week). Persons laid off 100 per cent are defined as unemployed after three continuous months of leave.
Persons in the labour force are either employed or unemployed. The remaining group of persons is labelled not in the labour force .
Man-hours worked include all actual working hours, i.e. including overtime and excluding absence from work. Persons absent from work are not included in the calculation of actual working hours per week (in average) .
Contractual/usual working hours refer to the weekly number of working hours determined by the working contract. Absence from work because of illness, holidays etc. is not subtracted, and overtime is not included. Employees, whose contractual working hours vary from week to week, give information on both the actual reference week as well as the average of their contractual working hours per week (in the tables published the average numbers are normally used). For employees without contract on working hours, for self-employed and for unpaid family workers, data on their usual weekly working hours are used (as an average of their actual working hours during the last 4 weeks).
Full-time/part-time distinction is based on the contractual/usual working hours. Part-time: 1-36 hours, with exception of persons with 32-36 hours who classify themselves as full-time employed.
Full-time: 37 hours and over, and the cases mentioned above. For persons with more jobs, the working hours in the main and the second job are summarized.
Overtime is defined as working hours which exceed the contractual working hours for full-time employees, conducted during a specified reference week. The overtime may be compensated by payment or by time off, or be without any compensation. Up to 2006 these questions were included in the survey only during the 2nd quarter each year. As from 2006 onwards they are included each quarter.
A major revision of the LFS in 2006 led to a significant break in the time-series for overtime, i.e. lower estimates than published earlier. This was mostly due to changes in the questionnaire concerning working time.
Statistics on overtime include employees working full-time only. For persons with more jobs, the working hours in the main and the second job are summarized in order to classify them as either part- or full-time workers, as in LFS statistics generally.
For those with more jobs, overtime hours in the main job only are included. By calculating the overtime hours as a share of the total number of man-hours worked among full-time employees, the working hours in the second job are, however, included in the denominator. Persons temporarily absent from work are included in the denominator while calculating the share of employees working overtime, mainly to avoid seasonal variations.
Employees who just had an occasional job in the reference week, and on-call workers, are not asked about overtime, but they are included in the denominator if they were full-time employed in the reference week.
As from 2007 imputation is used concerning the overtime variables in case of proxy interviews and partial non-response.
Involuntary part-time employment comprises part-time employed persons seeking longer contractual/usual working hours by registering at the Employment Offices, advertising, contacting present employer etc., and who were able to start with increased working hours within a month.
Permanence of the job
The employees are asked whether they have a permanent job (a work contract of unlimited duration) or a temporary job (a work contract of limited duration). If the person has more than one job, only the main job is classified by permanence.
There are two kinds of working arrangements outside ordinary hours (Monday to Friday from 6 am to 6 pm).
- Shift work is usually understood as working time outside normally working hours. What counts in the survey as shift work is based on the evaluation of the respondent. For respondents who have not answered the question on shift work, the value is imputed based on the answers they have given with regard to evening, night, Saturday and Sunday work.
- Work outside ordinary hours, not shift work. This refers to work on evenings, nights, Saturdays and Sundays which is not shift work. Evening work is defined as work between 6 pm and 10 pm. Night work is between 10 pm and 6 am. Respondents who report that they work on one or more of these working time schedules outside ordinary hours are also asked about the frequency of this kind of work during a four week period. This is done for each of the working time schedule separately. Based on this, the work outside regularly hours is divided into the categories "regularly" or "sometimes". For evening and night work, the respondent must have this kind of work on at least half of their working days in the four week period to be defined as having regularly evening work and/or regularly night work. For work on weekends, they must work 2-4 Saturdays and/or 2-4 Sundays during the four week period to be defined as having regularly Saturday and/or Sunday work. The respondents who have these kinds of working schedules, but more seldom than indicated above, are defined as sometimes having this kind of work.
Working hour arrangements outside ordinary daytime are based on the contract for the employees, and on usual working time pattern for the self-employed. Up to 2006 these questions were included in the survey only during the 2nd quarter each year. As from 2006 onwards they are included each quarter, but only for ¼ of the sample, and the results are published once a year: Labour force survey. Patterns of working time.
Course participation refers to job related courses which the respondent was paid to attend. Only courses received during a period of four weeks are included. Up to 2006 these questions were asked only during the 2nd quarter each year. As from 2006 onwards they are included each quarter to the whole sample. Labour force survey. Education and training.
As from 2006 the definition of age was changed from completed years at the end of the year to completed years at the time of the reference week.
The persons are classified by marital status as unmarried, married and previously married according to information given by the respondents. Previously married includes widows, widowers, separated and divorced persons. In the tables married women include cohabitants.
Immigrants are defined as persons born abroad by foreign-born parents who have emigrated toNorway. In statistics based on the Labour Force Survey (LFS) they are divided in two groups by country of birth:
1) Immigrants from EU/EFTA-countries,North-America,AustraliaandNew Zealand.
2) Immigrants from Eastern Europe except EU, Asia, Africa, Latin America and Oceania except Australia and New Zealand.
The industrial classification is in accordance with the Standard Industrial Classification (NOS D 383), which is based on the EU-standard of NACE Rev. 2.
The occupational classification is based on the International Standard Classification of Occupations 2008 (ISCO-08). The Norwegian standard has been named STYRK-08 (Notater 17/2011).
The educational classification is in accordance with the Norwegian Standard Classification of Education (NOS C617).
County and the whole country.
Frequency and timeliness
Quarterly and annual, but monthly publishing of some key figures seasonally adjusted (averages of the last 3 months). Quarterly figures are normally published 5 weeks after the end of the quarter.
The quarterly data files are sent to Eurostat. Tables are sent each month/quarter/year to Eurostat, OECD, ILO and IMF, as well as to the Nordic Yearbook.
The basic material (survey results from the interviewers) as well as the statistical files (on the basis of revision and estimation procedures) are stored.
Background and purpose
The main purpose of the survey is to provide data on employment and unemployment, and data on the labour force participation in different sections of the population. The Norwegian LFS started in 1972. For information about the history of the survey, and about breaks in the time-series, please cf. Labour Force Survey 2001 (NOS C748).
Users and applications
The surveys give information to the Labour Market Authorities and other users about the situation on the labour market, and provide data for labour force research and forecasts, as well as for international organizations and mass media.
Equal treatment of users
No external users have access to the statistics and analyses before they are published and accessible simultaneously for all users on ssb.no at 08 am. Prior to this, a minimum of three months' advance notice is given inthe Statistics Release Calendar.
For more information, see Principles for equal treatment of users in releasing statistics and analyses
Coherence with other statistics
The results from the LFS are used in the National Accounts Statistics.
For statistics at regional levels (counties and municipalities), the Registerbased Employment Statistics are recommended. These statistics also give figures on employees who are immigrants.
Statistics Norway also produces statistics on selected industries based on data from the establishments, containing figures on employment, compensation of employees, value of production and capital formation etc. These statistics contain more detailed information about each industry than it is possible to give from the LFS and the National Accounts Statistics.
Statistics on unemployed persons at the Employment Offices and government measures to promote employment are compiled by NAV on the basis of registers of unemployed persons and applicants for work.
The figures on unemployment based on the LFS differ from the figures on unemployed persons registered at the Employment Offices. The LFS-figures also include unemployed persons not registered at the Employment Offices, some of the participants in government measures to promote employment and some of the disabled persons. On the other hand, some of the registered unemployed are not classified as unemployed in the LFS, on the basis of the information given on seeking and availability for work. As from 2006 persons on lay-off (until 3 months) are no longer classified as unemployed, but as employed persons (temporarily absent from work) in the LFS, while they still are classified as unemployed in the registerbased statistics. However, if the period of lay-off exceeds 3 months, they are classified as unemployed in the LFS as well.
The Population and Housing Censuses (each 10th year) give statistics on employment during the last 12 months, in addition to the situation in a specified reference week. As from 2001 onwards employment data based on administrative registers are used. Statistics on labour conflicts and working days lost are compiled by Statistics Norway on the basis of information supplied mostly by the labour and employers's organizations. The Surveys of Level of Living (by Statistics Norway) give information on physical working environment as well as organizational working conditions.
The main source to describe the situation for the immigrants on the labour market is the registerbased statistics on employment and unemployment. By using data from the LFS as a supplement we will achieve still more information regarding this group, for example on actual and desired working hours, temporary employment and patterns of working time. Moreover the LFS has more data than the registers on job seeking and desire for work.
The main problem using the LFS for statistics on immigrants is the size of the sample and the statistical uncertainty. The group of immigrants in Norway is rather heterogeneous regarding their situation on the labour market, and therefore it is required to divide among at least two groups in the presentation of statistics. A further dividing by other variables will require long time-series in order to draw any conclusions.
The Statistics Act §§ 2-2 and 2-3.
Council Regulation (EC) nos 577/98, 1991/2002 and 2257/2003, and Commission Regulation nos 1575/2000, 1897/2000, 2104/2002, 430/2005 and 377/2008.
The total population aged 15-74 is covered by the LFS. Up to 2006 the group was 16-74, and age defined as completed years at the end of the year. As from 2006 age is defined as completed years at the time of the reference week. Observation unit: person.
Data sources and sampling
The main source for the LFS is quarterly, representative sample surveys based on interview by telephone.
Inhabitants in all municipalities are randomly selected, on the basis of a register of family units. The sample consists of about 12 000 family units (24 000 persons) each quarter. Each family member aged 15-74 participates in the survey, answering questions about their situation during a specified reference week. As from 1996 each family participates in the survey 8 times during a period of 8 quarters (before 1996: 4 times during 6 quarters). Up to 1996 a two stage sampling procedure was applied. For more information, please cf. Labour Force Survey 2001 (NOS C748).
Collection of data, editing and estimations
Interview by telephone. Information from previous interviews are used while asking about any changes in the situation, instead of the same, comprehensive data collection every time. For the coding of industry, information from some registers is also used. Demographic data are collected from the Central Population Register, and data on education are based on a register of individual data collected by Statistics Norway from the educational institutions (but questions are also asked to get more updated information).
The respondent is usually the same person as the observation unit (but proxy interviews are done if it is not possible to get in contact with the observation unit; 14-15 per cent of the interviews are done by asking near family members). Data are collected weekly, i.e. the LFS is a continuous survey (all weeks are covered). Up to 1st quarter 1996 (from 2nd quarter 1988) the survey was based on one reference week each month, and in previous years on one week each quarter. Participation in the survey is compulsory, but compulsory fines are not used.
As the data collection is made by use of computer-assisted interviews, some procedures for electronic control of the registration of answers are included in the questionnaire, for example concerning the number of working hours during the reference week. In some cases the interviewers become a "warning" by recording an answer, in other cases maximum or minimum values have been set beforehand.
The analysis unit is person. The absolute numbers from the LFS are presented in the form of estimated total for the entire population aged 15-74. The weights or inflation factors vary, but have an average of about 195 for quarterly figures in 2017.
The estimation method uses more demographic data and register information relevant to the connection to the labour market in order to minimize standard errors and correct more for bias in the response sample in LFS since the nonresponse is not random. New method was launched in April 2018, is also used on LFS data back to 2006 to get the most comparable time series.
The estimation method in LFS is done in several stages, and are called multiple model calibration (MMK). Initially, the main labor market status of LFS, which is employed, unemployed, outside the workforce, are modeled consistent with a multinomial logit model, explained with a number of register variables known to all in the population. The register information are registered completely unemployed, on measures and persons with disabilities at NAV, register information on disability pensioners, education level, marital status, family size and immigrant category, country of origin, gender and age, residence, and information from the A scheme and the Tax Recovery Register. The model provides predictive probabilities every month for each main labor market status in LFS for everybody in the population.
The monthly weights in LFS are calibrated using these predicted probabilities and some register variables directly. This means that the weights also become consistent with the population for the number in the population register by gender, different age groups and region, as well as consistent weights for the number of full / part-time wage earners by gender and registered employed (yes/no) cross classified by immigrants in 2 groups.
Multiple model calibration provides some variance reduction, utilizing more efficiently that we have available good help information about everyone in the population from various registries that Statistics Norway has linked.
The initial weights before calibration are the ratio of the number of people in the population to the gross sample per. county (NUTS3), and takes into account that people in different counties have different probabilities of being selected to LFS sample.
For more detailed technical information about the new estimation method, please see Documents 2018/16 [https://www.ssb.no/en/arbeid-og-lonn/artikler-og-publikasjoner/new-estimation-methodology-for-the-norwegian-labour-force-survey]
Week-proportional weighting of the months in quarterly averages
LFS have continuous data collection. In order for all reference weeks to weighted evenly in quarterly averages, we now make week-proportional adjustment of monthly weights in our quarterly averages. That is, the monthly weights are multiplied by 4/13 or 5/13 depending on whether the months in the LFS contain respectively 4 or 5 whole weeks. Weekly proportional weighting of quarterly average has been made on all quarterly figures in our StatBank back to 2006. Before that is the even adjustment off all monthly weights was used, i.e. multiplied by 1/3 for all months.
That the weights are consistent for a register variable, such as gender, means that the sum of the weights in the responses in the LFS equals the number of the population for each category of the register variable, such as the number of men and the number of women in the population
Quarterly figures from LFS are not seasonally adjusted
Comparability over time and space
New estimation method published in April 2018 uses more registers that will reduce nonresponse bias and sample uncertainty. This leads to a slightly lower level of employed and almost correspondingly higher levels for people outside the workforce than the previous method. The total number of unemployed changes only a little. To get the most comparable figures, the time series are revised back to 2006 in our StatBank. However, the adjustments vary slightly between groups and over time.
Breaks in the series up to 2001 are described in the publication Labour Force Survey 2001 (NOS C748).
The concepts in LFS are defined in accordance with international recommendations, cf item 4.1, to ensure comparability among the countries.
As from 2006 the LFS was revised, mainly to be in accordance with the EU-requirements based on new ILO recommendations. Some definitions and parts of the questionnaire were changed, and some new variables were added. As from 2006 age is defined as completed years at the time of the reference week, instead of completed years at the end of the year, as earlier. Moreover the lower age limit to be covered by the survey was lowered from 16 to 15, in accordance with the surveys in other countries.
These changes from 2006 led to breaks in the time-series for the LFS estimates. The revised survey gives some lower estimates for unemployment (1 000 persons as an annual average for 2006) and some higher estimates for employment (8 000 in 2006). A break in the time series also occured for the estimates of actual working hours per week and man-hours worked. For more information, please cf. http://www.ssb.no/aku_en/. Quarterly data for 2006 are published according to both the revised and the unrevised LFS, in order to improve the comparability for the figures between 2006 and 2005. The breaks in the time-series were most significant for figures divided by age groups.
Sources of error and uncertainty
In all surveys errors may occur in connection with both the collection and the processing of data. The use of proxy interviews (asking near family members instead of the observation unit) often increase the problems of measurement. As an average the employment is underestimated because of proxy interviews.
The size of the nonresponse as a percentage of the gross sample has varied widely since the LFS began in 1972. The 20 first years were generally around 10-12 percent. In the years 1992-1997 it was particularly low, only 6-8 percent. Subsequently, the nonresponse rate gradually increased to 21 per cent in 2013. After systematic work, the nonresponse has been reduced to around 16 per cent in 2017.
Correction for total non-response is done in the estimating procedure. Partial non-response is adjusted for some variables.
The standard error for the quarterly average for the number of unemployed aged 15-74 is around 4600 in 2017. It corresponds to a coefficient of variation of 3.9 per cent. The standard error for the quarterly average for the number of employed aged 15-74 in LFS is about 8600 people in 2017. The coefficient of variation for employment figures will then be around 0.29 percent. More calculations will later be published in our StatBank.
If the reader wants an indication of the size of the standard error for quarterly figures and annual averages for other variables or group divisions, see the table below. These indications are only guiding, and can not be interpreted as precise calculations for any variable. Changes between two surveys will usually have the same absolute uncertainty as the two figures which are compared.
As per cent of estimated value
As per cent of estimated value
1 000 000
1 700 000
2 000 000