Comparability

Comparability - geographical

There are only small differences between the definitions used in Denmark and in other countries, but they have no influence on the principal number level.

Comparability over time

The register

From September 2003, unknown owner/user disappeared as an option. All vehicles could then be placed on sector (household or business) and nearly all could be placed geographically.

Registers with population data

There have with a few exceptions been no alterations to the definitions of the variables since 1992.

The categories of highest employment status/job group in the family were replaced in 1996.

The definition of families was changed in 2006 where children < 25 years was included in the family. Before 2006 only children < 18 year was included.

The municipalities was changed in 2007 with the so called structural reform.

Publications

There are no substantial methodical changes with respect to the calculations of the different transaction and stock figures since 1992. There was however, a minor change in 1994 where the limit between vans and small lorries was moved from 3,000 kg to 3,500 kg. The stock of vehicles was thereby increased with approx. 90,000 vehicles.

There has during the years been some expansions in the figures mainly with new subdivisions to existing groups.

The transition to the Digital Motor Register, DMR has caused no breaks in data.

Seasonally adjustment

The models used for the seasonal adjustment are analysed and revised with regular intervals. The revision in 2015 changed the start year of the analysed series to 2007. The adjusted series that cover the period 2000-2014 and which can be found in the historical series in Statbank Denmark will not be re-estimated any longer. The application of the updated software to seasonal adjustment in 2016 has not changed the start year (2007).

Coherence - cross domain

The register

The used background variables from the register harmonize in terms of definition and grouping with uses of these within statistical areas from which they are obtained for the car statistics. There is, however, some discrepancy concerning the time of reference between the decided vehicle data and the background variables. At the time of calculation, the variables from the population statistics can be up to twelve months old, while the variables from the income statistics can be up to 24 months old. The publications: Compared with the new registration figures that are published monthly by Danske Bilimportører (the trade association of Danish car importers) minor differences are observed. These are mainly attributable to minor displaced extracts from the Central Register of Motor Vehicles and minor differences in the definitions and groupings of vehicles.

The publications

Compared with the new registration figures that are published monthly by Danske Bilimportører (the trade association of Danish car importers) minor differences are observed. These are mainly attributable to minor displaced extracts from the Central Register of Motor Vehicles and minor differences in the definitions and groupings of vehicles.

Coherence - internal

Data from the car register and family data:

There can be some discrepancy concerning the time of reference between the vehicle data and the background variables from other registers. At the time of calculation, the variables from the population statistics can be up to twelve months old, while the variables from the income statistics can be up to 24 months old.

There is internal coherence in the vehicle register.