13033_om_not-searchable
/en/priser-og-prisindekser/statistikker/lapi/kvartal
13033_om
statistikk
2008-09-01T10:00:00.000Z
Prices and price indices
en
false

Storrage and warehousing and offshore supply terminals, price index, Q1 2008

Content

About the statistics

Definitions

Name and topic

Name: Storrage and warehousing and offshore supply terminals, price index
Topic: Prices and price indices

Responsible division

Transport, Tourism and ICT Statistics

Definitions of the main concepts and variables

The price measured in this index is contract price on storage and warehousing services, exclusive VAT. The turnover used to weigh the index is obtained from the structural business statistics. Turnover -- is defined as the sum of revenue received from rendering services to customers and sales of merchandise, and gross income from other activities. Rental income and commissions are included, while special taxes, public grants and profit on the disposal of fixed assets are not. VAT is not included in the statistics.

Standard classifications

The storage services provided are divided into five subgroups/storage types. consequently, the price index for storage and warehousing is made up of five different sub-indices based on storage types. The sub-indices are: Frozen/cool storage, container storage, bulk storage, general storage, and storage of dangerous goods. Due to small number of observations in some of the sub groups we publish only three sub indices; a sub index for frozen/cool storage, a sub index for general storage and a sub index for other storage. The sub index other storage is a weighted average of bulk storage, container storage and dangerouse goods.

Administrative information

Regional level

National

Frequency and timeliness

Frequency: quarterly
Timeliness: The Statistics is published within 2 months after the end of the reference period

International reporting

Part of the Norwegian National Accounts reporting to Eurostat

Microdata

Data are stored as text files on UNIX.

Background

Background and purpose

The purpose of the index is to measure price developments in the storage and warehousing sector. The statistics were published for the first time in 2008, with figures going back to the 4th quarter of 2006.

Users and applications

Producer price indices are used as deflators in the National Accounts. They are also used to analyse and survey the development in prices and costs. Other potential users of the index for storage and warehousing include anyone with an interest in this market, for example Research and Development institutions and the media.

Coherence with other statistics

The index will be used in the National accounts. The weights used in index calculations are derived from the structural statistics of the industry. Detailed information on the structural statistics of the industry

Legal authority

The Statistics Act, Sections 2-1, 2-2 and 2-3

EEA reference

Regulation (EC) No 1158/2005 of the European Parliament and the Council of July 6 2005 amending Council Regulation (EC) No 1165/98 concerning short-term statistics.

Production

Population

The population is mainly defined as businesses in Norway classified under NACE 63.12 (storage and warehousing), SIC2002. In addition to this we also have few businesses engaged in storage and warehousing classified under 63.224 (Supply bases). The industry has many small actors as well as a few big ones, but enterprises with annual earnings of NOK 2 million or more account for about 98 per cent of the industry turnover. Hence, revenue of NOK 2 million is adopted as the cut off point that defines our population of interest. The enterprise is the statistical unit used in the survey.

Data sources and sampling

The sample is drawn from Statistics Norway's Business Register. Turnover figures are obtained from structural business statistics and the survey questionnaire covers the remaining variables of interest. The survey is carried out quarterly. Enterprises submit the questionnaire either online or by mail.

The sample size is approximately 31 enterprises with about 10-15 enterprises being rotated every 3rd year.

Collection of data, editing and estimations

The survey is based on information from the Business register, and paper or online questionnaires submitted quarterly by the survey participants. The questionnaires are dispatched by the end of each quarter with a two-week deadline. Respondents who haven't returned the questionnaire by the deadline will receive a postal reminder with a one-week extension of the deadline. If the questionnaire still isn't returned, the respondent is given another one-week final extension, and eventually a fine if data is not submitted by the expiration of the final deadline.

Questionnaires submitted by paper are entered manually into the database. Forms submitted online are downloaded automatically. Both types of questionnaires are subject to manual and automatic control and revision. Respondents may be contacted if serious errors or inconsistencies are identified.

First a price change per storage type is calculated for each unit in the sample. When a unit is represented by two or more observations for each storage type we use a geometric average. The units are classified into two different strata on the basis of unit turnover. Next, sub-indices for each storage type and stratum are calculated, and thereafter aggregated over strata to storage type. Finally, the sub-indices are combined to produce an overall index. Weights are assigned to the sub-indices that comprise the total index. The sub-indices are weighted according to turnover. The units are classified into two different strata on the basis of unit revenue. The index is calculated as Laspeyres Index with fixed weights based on turnover. The weights will be adjusted every 3rd year.

Confidentiality

Data compiled from respondents will be used in accordance with requirements set by the Data Inspectorate. The information will be stored securely and kept confidential.

Comparability over time and space

The time series started in the 4th quarter of 2006. The calculation method has remained unchanged.

Accuracy and reliability

Sources of error and uncertainty

Errors might be caused by misreporting. There are two main sources of measurement errors. One is that the respondent states the same price even though it has changed from one quarter to the next. The other is that the respondent reports prices on different services than the ones covered by the questionnaire. If a measurement error is suspected, the respondent is contacted to get the right price. Data is also controlled when the questionnaires are being read. In general, the production system ensures that the data is controlled on both detailed and aggregated level.

Non-response will always be a factor in questionnaire-based surveys. Some respondents do not return their forms, and some forms are rejected because they are incompletely filled out. Having said this, the non-response rate for this survey is marginal (less than 3 per cent).

The sample of 31 units constitutes over 60 per cent of the industry's population above the cut off point of NOK 2 million in turnover. Despite the big sample size, however, it is likely that some storage types might be underrepresented as our sampling unit is the enterprise and not a storage type. The sampling error has not been calculated.

The way the weights are constructed is another source of error. The share of storage and warehousing services in an enterprise's turnover can only be obtained from the survey. Figures from the enterprises are combined with the data from the Structural Business Statistics to arrive at a figure for storage and warehousing turnover. Consequently, the total storage and warehousing turnover refers to the sum of the revenues of the enterprises included in the sample, and not to the total industry turnover. As a result of this the weights might be downwards or upwards biased. But the fact that the sample encompasses about 98 per cent of the industry turnover minimizes this bias.

Standard errors and coefficients of variation are calculated alongside all index estimations. Storage types with few observations are more likely to be insignificant.