Data behind the wage statistics 1997–2014

In 1997, Statistics Norway established holistic, comparable and comprehensive wage statistics with uniform definitions and concepts. The statistical material is collected from public sector registers and sample surveys in all main industry classifications in the private sector, with the exception of the primary industries.

1. Production of the data collection and use of data sources

The wage statistics file is based on and compiled from the base data in the published wage statistics for all the years dating back to 1997. The file encompasses all employees included in wage statistics’ counts, full counts in the public sector and sample counts in the private sector.

The data collection is structured as an event history file, which means that all years from 1997 to 2014 are linked at the individual level.

In the wage statistics, the term ‘wage’ relates to the measurement of monthly earnings on a specific date in the year, not wage sums over an entire year or period. The count date is either 1 September or 1 October, depending on the industry. It is also important to note that retrospective payments of basic salary are not reported. In other words, the wages concept only encompasses wages that are paid excluding any retrospective payments. For example, in the event of late payment of a wages settlement, the retrospective payment from the settlement is not included. There is also no information to indicate at what point in the year the wages are earned.

The wage statistics are based on reported employment per individual and position per company. This means that an individual who holds more than one position will have more than one observation in the wage statistics file. It is not the individual that is the central unit of measure, but the individual’s position. Personal identification number duplications in the file therefore signify that the holder holds more than one position.

The file is composed of separate base data for both the public and private sectors. For the public sector, the statistical basis is obtained from the State Central Register of Government Employees (SST) for central government employees and the Personnel Administration Information System(PAI) for municipal employees (including the school system from 2004). Prior to 2004, employees in the school system were reported in the Central Register of Government Employees in the School System (STS).

The material in the part of the statistical data that is based on a sample is weighted. The weighting corresponds to the inverse selection probability, adjusted for employment changes. This means that the sum of the weights corresponds to the total employment on the count date.

See also: Wage statistics in the private sector 1997–2001 (Notater 2003/74, in Norwegian)

The wage statistics for the public sector from earlier years lack information about organisation number, industry codes and occupation codes.

2. Content of the file

For a full description of the file, see Section 5. Some of the main variables are covered here, and are also linked to more detailed information at ssb.no.

Population

The wages file is structured as a file at individual level, with identifiers for each employee (wage components, working hours, occupation, etc.), linked to local unit (company) and legal entity (enterprise). The identifiers associated with local units are linked from Statistics Norway's Central Register of Establishments and Enterprises (industry code, etc.).

It is important to note that the wage statistics are based on separate samples of enterprises for each year and within each industry in the private sector. The number of individuals that can be followed from year to year will therefore be limited. In simple terms, the sample method is based on stratified random, systematic cluster samples. Stratification takes place at enterprise size (number of employees) in each industry, with a full count among the largest enterprises, and a cut-off point among the smallest.

The material is weighted in order to correspond to the population at the time of the count See the section on weighting above.

Variables

The wages concept in the wage statistics is limited to cash remuneration from employer to employee for work performed. Consequently, the statistics do not include fringe benefits, insurance or tax-free expenditure allowances and such like. See further explanations of terms used in the wages concept.

Monthly earnings

Monthly earnings is the main term used in Statistics Norway’s wage statistics. Monthly earnings cover basic salaries, variable additional allowances and bonuses. Overtime pay is not included in monthly earnings.

Basic salary

Basic salary refers to the fixed basic amount (calculated as monthly earnings) that is paid as either payment by the hour, week, fortnight or month. Basic salary is the actual payment at the time of the count, and is often described as a salary according to a scale or a fixed basic wage. Additions for qualifications/skills and other fixed personal additions are included in this type of wage.

Variable overview

3. Quality

Sources of error in the statistical basis are mainly errors and uncertainties related to the wage statistics that serve as the source of the statistics.

Errors in registers used for stratification and sample selection, incorrect entries of wage types, working hours or other variables in the form, errors in input or registration of reported information, or errors and missing information that is linked from other sources. Further details are available in About the statistics.

4. Wage or income?

Wages represent the remuneration received for work performed in a job, while income is a broader term that includes, among other things, income from self-employment, capital income and other transfers. Read more.  

5. Why are the wage statistics not part of the employment statistics?

The wage statistics only include employees; not those who are self-employed, while the employment statistics encompass both of these groups. Read more.

6. Trends in monthly earnings 1997–2014

Figure 1. Average monthly earnings for full-time employees, by gender

Figure 2. Change in average monthly earnings for full-time employees