Accuracy and reliability

Overall accuracy

The annual statistics are based on an exhaustive census among holiday house rental agencies having 25 or more individual holiday houses at disposal. The data in the statistics is considered accurate regarding the number of rented houses, contracts and houses for disposal. Number of nights is considered less accurate. There might be a few small holiday house rental agencies which is not part of the survey because Statistics Denmark and VisitDenmark are not familiar with these. The absence of those few small agencies do not have significance for the results in overall. Usually the changes from year to year are like the the changes reported by the largest holiday house rental agencies.

Sampling error

None. It is an exhaustive census for holiday house rental agencies with a minimum of 25 houses for disposal.

Non-sampling error

There might be missing some few holiday house rental agencies with a minimum of 25 houses for disposal, due to no official register, however all big agencies are considered as included and therefore the lack of those few small rental agencies is not considered significant. The bias concerning the size of the rental agencies - the minimum of 25 houses for disposal is not calculated. There is no register of holiday house rental agencies with less than 25 houses for disposal. Likewise there is no official calculation of rental through online global platforms like airbnb or hotels.com. Privately held rental of holiday houses is not part of the statistics. The number of nights is slightly uncertain as it might be reported based on estimates.

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 survey is a total census aimed at all holiday house rental agencies in Denmark with a minimum of 25 houses at disposal and a direct billing obligation to the owner. There is no official register of holiday house rental agencies, so the population is updated based on internet information, inquiries from the rental agencies and lists from VisitDenmark. There is thus uncertainty as to whether all relevant rental agencies are involved. However, since the population is relatively consistent from year to year, the numbers are comparable from year to year in terms of percentage changes.

In 2011, the overnight figures for 2010 were adjusted upwards by 647,000 as a result of revised information from some rental agencies. As a consequence, the number of overnight stays in 2010 and 2011 and onwards is not immediately comparable with the number of overnight stays in previous years.

The statistics have more or less uncertainty in the various variables, depending on the lessor's report. The variables number of contracts (bookings), number of houses available and number of house-weeks let out are considered to be the most reliable. The figure for the number of overnight stays more uncertain, since the number is estimated based on numbers of persons pr. house week.

is considered to be more uncertain, as the figure may be based on estimated reports of the average number of people per night. house week.

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

The statistics are not generally revised. Revisions are however made later if serious errors are discovered. Thus, the overnight figures for 2010 were adjusted upwards by 647,000 in 2011 as a result of revised information from some rental agencies. As a consequence, the number of overnight stays in 2010 and 2011 and onwards is not immediately comparable with the number of overnight stays in previous years.