Accuracy and reliability

Overall accuracy

Compiled on total turnover for EGSS, the error is expected to be plus/minus 10-15 billion DKK (related to a level for output at 250 billion DKK). The main part of the total error are considered to be due to measurement errors.

For value added, employment and export, the errors are of at least same size, relatively, as data are linked.

There is no knowledge if the results are over- or underestimating the "true" value.

Sampling error

The variance (CV) on the total estimate for turnover of EGSS in the surveyed types of industries is calculated to about 1,5 per cent . Its correspond to an error on 3 billion DKK, as the turnover in the subpopulation is 200 billion DKK.

For the single types of industries the error is higher, relatively. The typical variation is about 10 per cent.

On smaller units (less than 50 employees) the error is about 10 per cent. For larger holdings about 1,5 per cent.

Non-sampling error

The errors from other reasons than sample survey is measurement errors. It is difficult exactly to assess if a good or service is part of EGSS or not.

What matters other variables than turnover, the assumption is, that an EGSS share of turnover also reflects the EGSS share of export, value added and employment. Furthermore, it is assumed that 2013-data also could be used for 2012 and 2014 compilation - 2015 data for 2016 compilation, 2017-data for 2018-compilation, 2019-data for 2020-compilation and 2021 data for 2022 compilation.

The results for export is underestimating the real level, due to problems to connect data on production and export. It is assessed, that the und

erestimat

n 10 per cent.

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

There are several sources of errors, which are considered to induce uncertainty to the results for environmental goods and service. In particular, this is due to the level of clarity of definitions on EGSS. This size of this problem has been reduced by very intensive validation of data.

In particular service in EGSS can be difficult to estimate, as EGSS services often is a part of a comprehensive process. Isolation of buildings is most often part of repair or construction and the time spend on the EGS is not easy to estimate. Further, advisory service also contains elements of EGSS, but difficult to distinguish between EGSS and non-EGSS.

EGSS-data from existing statistical sources is considered to be of good quality. Is is difficult to access the quality of the estimated figures (since 2017) for the construction sector.

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

There have no been recent revision as regards turnover, employment and value added. Provisional results are updated to final figures in the consecutive year.

The export results for 2012-2014 has been revised, due to revisions in the original results.