Principle 14: Coherence and Comparability
European Statistics are consistent internally, over time and comparable between regions and countries; it is possible to combine and make joint use of related data from different sources.
Indicator 14.1: Statistics are internally coherent and consistent (i.e. arithmetic and accounting identities observed).
In addition to the editing and imputation procedures that national statistical authorities apply to the national data collections, Eurostat production units check the internal coherence and consistency of the data received. These procedures are regularly reviewed and updated if required, as part of Eurostat's quality assessments.
Indicator 14.2: Statistics are comparable over a reasonable period of time
The coherence and consistency checks applied to the data by Eurostat production teams include analyses of data over time. Comparability over time is assured by minimising the frequency of changes to standards, classifications and coding of variables. A trade off between relevance and comparability over time is also considered.
Indicator 14.3: Statistics are compiled on the basis of common standards with respect to scope, definitions, units and classifications in the different surveys and sources.
Eurostat's task is to provide the European Union with statistics at European level that enable comparisons between countries and regions to be made. Eurostat therefore promotes the use of common standards for European statistics. These are specified either in the relevant legislation for the statistical collections or in European Statistical System agreements.
The extent to which common standards are implemented in different statistical areas is regularly assessed as part of Eurostat's quality assessments.
Indicator 14.4: Statistics from the different sources and of different periodicity are compared and reconciled.
In addition to the internal coherency checks applied to the data received from national data providers, analyses to reconcile data from different sources are also carried out – for example the regular monitoring of consistency between balance of payments data and foreign trade statistics. BOP, GNI and GFS data are regularly cross-checked against main GDP aggregates and inconsistencies are clarified with Member States if necessary.
Indicator 14.5: Cross-national comparability of the data is ensured within the European Statistical System through periodical exchanges between the European Statistical System and other statistical systems. Methodological studies are carried out in close co-operation between the Member States and Eurostat.
Eurostat develops and promotes common statistical standards and methods at an international level. There is a close coordination with the European System of Central Banks in the field of monetary and financial statistics, in addition to the statistical cooperation with the United Nations Statistical Division and the Organisation for Economic Co-operation and Development.
The ESS classifications are developed in close collaboration with other international organisations (e.g. UNSD, UNESCO and ILO). Also, the Statistical Data and Metadata eXchange (SDMX)
standards are created and applied at international level.