Statistical processing

Source data

The producer price index for refurbishment and maintenance are calculated on the basis of prices reported by selected companies. The sample is selected using a top-down approach, where the largest companies, based on turnover, are selected for price reporting.

Frequency of data collection

Yearly.

Data collection

For the producer price index for refurbishment and maintenance the prices are collected through an electronic reporting form via Business in Denmark, which is sent to relevant contacts within the selected companies.

Data validation

The first validation of the reported prices takes place when data arrive to Statistics Denmark. Here they are auto tested for unusual developments. If the change in prices is greater than a predetermined threshold value, then these prices will be checked manually by the staff and will only be accepted if the reporting company can verify the change. When all prices are in the system, a validation report will be generated. This report includes information on all price changes and measures the effect of these on the elementary aggregates. The final validation is a qualitative inspection of the calculated index tables.

Data compilation

The Producer price index for renovation and maintenance is calculated in a hierarchical system, where the collected prices are divided into groups identified by kind of activity. These groups are then aggregated into so-called elementary aggregates for which basic prices can be calculated. The development of basic prices between two periods is used to calculate basic indices, which are weighted together to form aggregated price indices, so-called sub indices. The sub indices are then weighed together to calculate the main index. The weight basis is based in information from the Danish Technological Institute on the refurbishment activity of Danish craftsmanship companies.

Adjustment

No corrections are made beyond what has already been described.