News 14 Apr 2020

Restrictions caused by coronavirus have an effect on data collection for the Consumer Price Index

The coronavirus has restricted the activity of our society already for a month. The effects of the restrictions will be visible in the statistics and the time series produced by them, but we already have to assess how the restrictions influence the data collection of statistical data. The changed situation is also taken into consideration in the data collection and data processing of the Consumer Price Index.

It is important for the quality of the Consumer Price Index that data collection is made in a similar manner from one month to the next. The collection of data has usually been made as a field collection around Finland and centralised at Statistics Finland. Some of the data are collected by interviewers in shops, some come as mass data including sales transactions direct from enterprises’ data systems for data processing and some of the data are collected from the Internet or other sources.

Because of the restrictions on movement, conventional data collection cannot any more be implemented as a field collection, but it must be replaced by alternative methods. Alternative collection methods are used so that the price collection data would not have too many missing prices.

In covering for missing data, the methods used are in the order of implementation as follows:

  1. Prices of corresponding products or services are gathered from the enterprise’s Internet pages or by telephone collection
  2. Missing prices are replaced by prices in the enterprise's mass data with prices corresponding to the products in the collection
  3. Missing prices are replaced with corresponding data of another outlet
  4. A missing price is imputed (missing observations are covered for with corresponding values) by the price change of other products or services in the same commodity group
  5. The previous collected price data are taken as the price of the present month (so-called carry-forward).

 

For March the price collection was implemented more or less with the conventional manner. For some commodity groups the imputation level describing missing prices rose slightly compared to an average month. More imputation of missing data has to be done in April, because then the collection of data will not be implemented to the conventional extent. Information on these changes will be given in connection with the release for April.

Read more: Impact of the COVID-19 virus on the data collection, data processing and index calculation of the Consumer Price Index (pdf)

Consumer Price Index

Further information: Senior Statistician Kristiina Nieminen, tel. +358 29 551 2957