The National Statistical Offices (NSO) in the countries in Northern Europe (Norway, Sweden, Finland and Denmark) have developed production systems that are based on statistical registers. Almost all surveys done by the Nordic NSOs are based on these systems of registers. Besides all register surveys that use these registers also sample surveys and censuses use the register system for creating frames and utilizing register variables as statistical variables and as auxiliary variables used for estimation.
These ways of using registers for statistics production are well-known and many countries are developing their production systems to become more and more based on registers as in the Nordic countries. However, the system of registers has features that have not been generally recognized: it opens possibilities to work with quality assessment and nonsampling errors in a new way.
All registers can be compared at the microdata level and also all sample surveys can be compared at the microdata level with all registers in the system. Systematic comparisons between samples surveys and registers in the system will give new knowledge of quality in different surveys and also give new possibilities to redesign surveys and improve the quality of the surveys in the system.