Accuracy and reliability

Overall accuracy

The margins of statistical uncertainty associated with the IPC are related to the statistical uncertainty of WTA.

In the long run (12 months), there is a good agreement with the National Accounts gross value added for the construction sector.

Sampling error

Not relevant for this statistics

Non-sampling error

The index is based on the WTA and has no independent uncertainty. However the most recent month is estimated to adhere to EU requirements. See the Documentation of the WTA.

Quality management

Statistics Denmark follows the recommendations on organisation and management of quality given in the Code of Practice for European Statistics (CoP) and the implementation guidelines given in the Quality Assurance Framework of the European Statistical System (QAF). A Working Group on Quality and a central quality assurance function have been established to continuously carry through control of products and processes.

Quality assurance

Statistics Denmark follows the principles in the Code of Practice for European Statistics (CoP) and uses the Quality Assurance Framework of the European Statistical System (QAF) for the implementation of the principles. This involves continuous decentralized and central control of products and processes based on documentation following international standards. The central quality assurance function reports to the Working Group on Quality. Reports include suggestions for improvement that are assessed, decided and subsequently implemented.

Quality assessment

The index is based in the WTA.

Data revision - policy

Statistics Denmark revises published figures in accordance with the Revision Policy for Statistics Denmark. The common procedures and principles of the Revision Policy are for some statistics supplemented by a specific revision practice.

Data revision practice

Since the Danish IPC is calculated on the basis of hours worked from the Working Time Accounts (WTA) statistics the revisions follow the same pattern. The first publications of the production in the first and second month of any quarter, is partly estimated, which means that for every publication of data for the third month in a quarter, when all data is actually available, the published figures for the first two months of that quarter is revised.

In addition to these quarterly revisions there are annual revisions on the hours worked from the WTA which also means revisions in the IPC. The structural data is first available more that 15 months after the year of reference, and the revisions will therefore cause revisions to the WTA and hence the IPC over two years back in time.