Accuracy and reliability

Overall accuracy

The accuracy of HFCE estimates by purpose depends on the quality and coverage of the underlying data sources and estimation methods applied. The overall level of HFCE is considered relatively robust, as VAT data provide an important benchmark for the total level of household consumption. However, greater uncertainty is associated with the distribution of HFCE across consumption purposes (COICOP18-classification). This distribution is affected by the sampling uncertainty and potential underreporting in the Household Budget Survey (HBS), as well as the use of estimates and assumptions for certain components of HFCE by purpose.

Uncertainty is highest in the earliest estimates, where detailed source data are not yet available. In these, estimates are based on short-term statistics and retail trade indicators, and the COICOP distribution is extrapolated from the latest final year. As more detailed and comprehensive data sources become available, they are progressively incorporated into the national accounts, reducing uncertainty in both levels and distribution of HFCE by purpose.

The use of multiple data sources and the integration of HFCE into the Supply and Use Tables (SUT) balancing framework contribute to the overall accuracy and consistency of the estimates.

Sampling error

Not relevant.

Non-sampling error

Non-sampling errors in HFCE arise mainly from coverage, measurement, and classification issues in the underlying data sources, as well as from estimation procedures used in the compilation process. Many of the data sources used in the HFCE are not fully comprehensive. As a result, adjustments are made to achieve full coverage of household consumption expenditure. This includes assumptions for areas where direct data are limited, such as fringe benefits and parts of the informal economy, where underreporting may occur.

Classification issues in HFCE mainly arise when integrating different data sources (e.g. VAT, retail trade statistics and administrative data) into a consistent COICOP-based national accounts framework, as well as aligning source data with national accounts concepts. The Household Budget Survey is collected according to COICOP, but minor inconsistencies may occur when the data are used in the national accounts due to harmonization of different data sources.

Additional non-sampling errors arise from estimation methods, including the use of indirect indicators, extrapolation of COICOP distributions from previous periods, and balancing adjustments to align different data sources.

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 ESA 2010 regulation requires that Eurostat assess the quality of data reported under the ESA transmission program. The quality assessment covers HFCE by purpose. The quality assessment is based on standard quality criteria defined in the European Statistical System, including relevance, accuracy and reliability, timeliness and punctuality, coherence and comparability, and accessibility and clarity. Quality reports for national accounts, which includes HFCE, are available on Eurostat's homepage under Quality reports.

Information on quality management, revision practices and methodological documentation is publicly available on Statistics Denmark’s website, while the detailed country-specific quality reports submitted to Eurostat are not published separately.

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

HFCE by purpose is revised according to the same principles as the national accounts as a whole. Ongoing revisions may occur when new or updated sources become available. In the quarterly and annual accounts, changes from the sources are incorporated as more complete data become available, which may lead to adjustments of previously published figures.

Indirect revisions may also occur when changes in the sources affect the accounting of the economy’s total supply and use. Such changes can affect the overall product balances and, consequently, the functional distribution, including household consumption.

Comprehensive revisions are carried out as part of the national accounts’ five-year revision cycle. During these revisions, longer time series for HFCE are updated to ensure consistency with the other components of the national accounts and to incorporate any changes in methodology, classifications, or source coverage. Larger revisions may also occur in connection with the implementation of new international standards, such as ESA, where the entire time series back to 1966 is re-estimated. e The latest benchmark revision of the Danish national accounts was carried out in 2024 as a part the HR2024 main revision. For HFCE by purpose, one of the main changes was the replacement of the previous European Classification of Individual Consumption by Purpose (ECOICOP) by the COICOP18. In addition, revisions to other parts of the SUT and the associated balancing process resulted in revisions to HFCE by purpose. The benchmark revision therefore resulted in changes to both the level and distribution of HFCE across consumption purposes as a result of the overall revision of the national accounts.