The statistic is published since 1984, and is in the current shape comparable from 2008 and forward. The statistic shows commuting within and across municipalities in Denmark, and the data foundation is based on administrative registers with national features. It is therefore difficult to compare the statistic internationally.
New and better data foundations and changes in the labour market have caused a number of data breaks over time, which have influence on the possibility of comparing data over time.
Statistics on commuting and mobility on the labour market is published in other countries and with different methods. Since there is no EU-regulation on the area there is no common international methodological guidelines for commuting statistics. Besides from that national features means that it is difficult to compare the statistic internationally. The Danish commuting statistic contains commuting within and across Danish municipalities, and the data foundation is further more based on administrative registers.
The statistic has been published since 1984. Over the years some changes have been done in the data foundation RAS, which have influence on the possibility to compare the statistic over time. Particularly the following data breaks in RAS is important to the commuting statistic.
In 2003 (November 2002) there is a data break in the time series. Changes on the labour market had created a need for different alterations in the statistic. The alterations in the statistic caused among other things a change in the order of priority for persons in more than one condition. For example the priority for persons who receive early retirement pay and worked at the same time was changed.
From November 2008 the eIncome-register is the data source for employment for employees. That causes a larger data break. The eIncome-register is based on monthly information from employers. That implied that the information concerning the period of employment got a higher quality. It also implied that the level of employment got lower due to the transition to the eIncome-register.
When producing RAS November 2008 in 2010 Statistics Denmark’s own version of the eIncome register was not yet ready. Therefore an early version of the eIncome-register based on the monthly reports made by the tax authorities was used for the statistic. When producing RAS November 2009 in 2011 Statistic Denmark’s own monthly eIncome-register was ready. It was realized that there were relatively large differences between the yearly version from the tax authorities and the monthly register which made it necessary to revise the statistics for November 2008.
New data foundation for RAS in 2015
In April 2015 the data foundation for RAS changed to be the Labour Market Account (LMA). In this context the commuting statistic was revised back to November 2008. In the same context the dating of the statistic changed, so that the time of reference from there is the end of November. That means that the statistic now is called e.g. November 2013 whereas it would earlier have been called 2014. Learn more about LMA here. When publishing RAS (end November 2014) in 2016 the time series November 2008-November 2013 was revised. Hereafter the plan is to do no further revisions of the historical time series.
Changes in Danish Industrial Classifications
In 1993 the classification changes from DSE77 to DB93. In 2003 it changes to DB03, and ind 2008 to DB07. Read more about the changes and the classification here.
The commuting statistic is published on municipal level in the StatBank. From November 2006 the statistic is published on the new municipals after the structural reform. In the period November 1980-November 2006 the statistic is made up on the municipals before the structural reform. November 2016 is therefore published with data from both before and after the reform.
The commuting statistic is like RAS comparable in the current form from 2008 and forward.
The commuting statistic is based on a subpopulation in RAS. A commuter is defined by being employed in RAS and besides of that have an address of residence which is different from the workplace address. It is therefore possible to connect the information about commuting distance with other detailed information from RAS. The commuting distance is furthermore the foundation of the border commuting between Denmark and Sweden. Read more about commuting in Oeresund.
The data foundation RAS is based on the Labour Market Account (LMA) which is compiled on a number of different sources. RAS is the result of an inventory at the end of November in LMA. Minor differences is however possible between the newest current version of LMA and RAS and thus the commuting statistic. That is because LMA is a more "lively" register where different improvements are done after the production of RAS. Improvements that have greater meaning to a longitudinal register (like LMA) than to a inventory (like RAS).