What does the survey comprise?
Quantification of the development of the contractual wages (also known as negotiated wages), contractual wage costs and contractual working hours of employees in the Netherlands who have a collective labour agreement.
Employees in the Netherlands who are covered by collective labour agreements (cao).
Contractual wages (cao wages) of employees in the Netherlands.
Year survey started
The current series 2020=100 starts in 2020, but this statistic have been published since 1926. Since the series 1980=100, a base shift takes place every ten years.
The results are published in an index form, starting from 2020, that is set to 100. The monthly figures are published within one week after the relevant calendar month. These are called the first-published figures. Thereafter, each month the index is revised based on new concluded collective labour agreements.
There are two versions of the results: current figures and first-published figures.
Current figures are the most recent figures for the whole series.
First-published figures are outdated. They are the first ever published figures for each reporting period from January 2020 and they will not be revised.
Current figures with * are provisional figures. This figure can be reviewed every month based on new collective labour agreements until the second quarter. In this month the figures of the previous calendar year become final (current figure without *).
Besides monthly figures, also quarterly and annual figures are published. These figures are calculated as the average of the quarter or year. In addition, also year-on-year changes are published.
Results on contractual wage costs and the percentage of concluded collective agreements are published in less detail than the results on the contractual wages and contractual working hours.
How is the survey conducted?
Collection of data on wages and working hours as listed in the concluded collective labour agreements (cao).
The index of contractual wage costs are based on contractual wage amounts plus legal and contractual employer contributions for pensions, early retirement, unemployment, sickness, disability and social funds.
Companies, institutions as well as labour unions and employers' organizations involved in concluding collective agreements.
The Netherlands has approximately 800 collective labour agreements, of which 600 concern at least a hundred employees. This statistic includes 208 collective labour agreements. These are in principle all major collective labour agreements (from 2 500 employees) and a sample of smaller agreements. In this way, approximately 95 percent of all collective labour agreement employees are directly represented in the results.
Methods for control and adjustment
Data on newly concluded collective labour agreements are viewed and compared with each other as much as possible from different information sources. The data from final negotiating agreements will later be checked against the final collective labour agreement texts.
The individual collective wage developments are combined and weighted by using the wage sums. This also includes employees who do not have a full-time job and employees who are not covered by a collective labour agreement. Three out of four employees are within the scope of a collective agreement.
Quality of the results
When an index is published, the figures of all known collective agreements are incorporated. Collective agreements whose term has expired, and for which no new collective agreement has been agreed upon, are not included in the month from which the new collective agreement should have started. In addition, preliminary labour agreements are not included. The percentage of concluded collective agreements shows what percentage of collective agreements the outcome is based on. The agreements mentioned above concerns relative weights of the collective agreements. This weight is set by the sum of all wages that is covered by the collective agreements.
Collective agreements can also be retroactively concluded. Therefore, each subsequent month the indices are recompiled and published.
The results of the series 2020=100 form a sequentially comparable series.
There is a monthly verification of the availability of new information on collective wages or contractual labour costs. Once every ten years, the basic data for the series of collective labour agreements are re-based.