Accuracy and reliability

Overall accuracy

Based on the sources for this statistics the overall accuracy is considered high for these statistics. There is a higher uncertainty related to the latest published year, since some sources are still being validated, while others have been subject to imputation. The uncertainty related to STEC is highly related to the uncertainty for ITSS. On the aggregated level ITSS is accurate, due to the large share of the trade that is directly reported, but on more detailed service items levels, the variance of the uncertainty is larger, mainly due sampling error.

Sampling error

The sampling error for the ITS survey is calculated with a CV value of the 0,6 pct. for exports and 0,8 pct. for imports.

Non-sampling error

Other uncertainty can be related to the sources of the statistics. The main source is International Trade in Services where an important element of inaccuracy is attached to the frame from which the sample is drawn. The frame was first derived from the settlement statistics of Danmarks Nationalbank, which was abolished in 2004. Effective from 2009 a new frame has been taken into use. This frame has been delimited from Business register and special screening surveys conducted every fifth year, last time in 2013, where 5.000-6.000 firms have been questioned. Finally it must be considered that the concepts being employed in the statistics are rather complicated. Accordingly misunderstandings in the reports leading to inaccurate compilations are unavoidable. This problem is constantly addressed by contacting the reporters when suspicions of misunderstandings are raised. Special analyses have been conducted on the items sea transport, travel, insurance, merchanting, government services (n.i.e.), construction services, and services between affiliated enterprises (n.i.e.) and most lately on intellectual property services. The travel item entails some difficulty, especially travel debits. It is compiled using different information on consumption by Danes abroad, number of nights abroad, and transport abroad from statistics from other countries; but the risk of error is fairly big, particularly concerning small partner countries. This error margin can, however not be calculated.

Further information on the accuracy of ITSS can be found in the dissemination report for ITSS: Dissemination report for international trade in services statistics.

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

STEC is of high quality. It is relevant for our users as it covers user needs which have not previously been met. These statistics are also consistent and comparable over time. The quality is as good as the sources used for compiling. For more information on the sources see the documentation of statistics for International Trade in Services, foreign owned enterprises and foreign affiliates abroad.

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

These statistics are revised by each publication date for the latest 2 year. This follows the revision policy of International Trade in Services and National Accounts.