About the statistics

1. Administrative information

1.1. Name

House price index

1.2. Subject group

08.02.30 - House price indices and construction cost indices

1.3. Frequency and timeliness

The house price index is published quarterly, about 15 days after the end of the relevant quarter.

1.4. Regional level

Norway is divided in eleven geographical regions, of which four are cities.

Oslo and Bærum
Stavanger
Bergen
Trondheim

Akershus without Bærum
South Eastern Norway
Hedmark and Oppland
Agder and Rogaland without Stavanger
Western Norway without Bergen
Trøndelag without Trondheim
Nordthern Norway

In addition, average square metre prices are published quarterly for the counties and yearly for the municipalities.

1.5. Responsible division

460 - Division for Construction and Service Statistics

1.6. Legal authority

Not relevant.

1.7. Legal document(EU)

Not relevant.

1.8. International reporting

Not relevant.

2. Background and purpose

2.1. Purpose and history

The purpose of the house price index for existing dwellings is to provide price statistics for the housing market. The index has been published since the first quarter of 1991.

2.2. Users and applications

The index is used by the public sector (the Ministry of Finance, Norges Bank, etc) and the financial industry. It is also used by people with an interest in the housing market, for instance private persons, research institutions and the media. The index is an important indicator for sellers and buyers of dwellings as well as for valuation and estate agencies.

3. Statistics production

3.1. Population

The house price index measures the development of the value of the total housing stock in Norway, based on price information from dwellings sold on the free market.

3.2. Data sources

Statistics Norway receives data from FINN.no AS through cooperation with the Norwegian Association of Real Estate Agents (NEF) and the Association of Real Estate Undertakings (EFF). FINN.no cooperates with most important real estate agencies in Norway.

3.3. Sampling

All sales registered by FINN.no.

3.4. Collection of data

FINN.no sends electronic reports of their sales monthly.

3.5. Control and revision

Machine controls ensure that dwellings with particularly small or large useful floor spaces or very high or low square meter prices are not included in the calculation of index.

3.6. Estimation

Sub-indices for three housing classes and eleven regions are calculated by using the hedonic method. These 33 sub-indices are weighted into total indices for each region and for the country as a whole. The weights are the estimated total value of housing stock of each housing class and within each region.

3.7. Confidentiality

In the square meter price section, numbers based on fewer than 10 observations are not published. This typically applies to the house types of row houses and flats, in the more sparsely populated counties.

4. Concepts, variables and classifications

4.1. Definitions of the main concepts and variables

Price is the registered purchase price of the dwelling. For co-operative dwellings, both deposit and joint debt is included in the price. Useful floor space is the floor area measured within the outer walls, excluding cellars, non-habitable attics and, in multi-dwelling houses, common spaces. The statistics is devided into two types of ownership; freeholder and housing co-operatives

4.2. Standard classifications

Not relevant.

5. Sources of error and uncertainty

5.1. Measurement and processing errors

Errors can occur during the data registering and processing done by the data suppliers (FINN.no, Notar AS and NBBL).

5.2 Non-response errors

Not relevant.

5.3. Sampling errors

The sample covers about 60 per cent of all dwelling-sales on the open market. Systematic skewness is still possible in the sample, regarding housing standard and location.

5.4. Other sources of error

The hedonic model used in the compilation of the house price index and does not adjust for housing standard. The index is therefore expected to overestimate the price increase.

6. Comparability and coherence

6.1. Comparability over time and space

Changes in data collection Until the first quarter of 2002, the price index for second-hand dwellings was produced using a quarterly survey. A questionnaire was sent to all registered purchasers of second-hand freeholder dwellings. Information from the survey was combined with information collected from the Ground Property, Address and Building Register (GAB).The compilation method was the same, but the number of explanatory variables in the regression model was more comprehensive.

New weighting The method for calculating weights has been changed twice since Statistics Norway started compiling the house price index in 1991. From 1991 to 1997, the total number of sales in each category was used as a weight. From 1997 to 2002, each category’s share of the total housing stock was used as a weight. Finally, from 2002, each category’s share of the value of the housing stock is used as a weight. The change in 1997 implies that regions with relatively few sales are given a stronger weight and the change in 2002 implies that regions with high price levels are given a stronger weight. From 2009 the country is devided into more regions. This means that the subindices are weighted together on a lower regional level than before.

Change in floor space concept Until 2002, utility floor space was used to calculate square metre prices. Following the change in data collection in 2002, useful floor space is used. Square metre prices are therefore not comparable before and after the first quarter of 2002.

6.2. Coherence with other statistics

The Norwegian Association of Real Estate Agents (NEF) produces house price statistics, which monitor the national and regional prices on a monthly basis. The differences in the price increases are mainly caused by different methods of weighting.

7. Availability

To access all published figures, use the link "More tables in StatBank" on the left hand side of the screen.

7.1. Publications and other links

The house price index is published quarterly in Today's statistics on Statistics Norway's website: http://www.ssb.no/bpi_en/.

The results are also published in the Statistical Yearbook.

Documentation:

Christensen, Thor Herman (2003):Boligprisindeksen: Datagrunnlag og beregningsmetode. Notater 2003/83. Oslo: Statistisk sentralbyrå. (In Norwegian only)

Jensen, Roger (1999):Beregninger av usikkerhet for boligprisindeksene på grunn av frafall. Rapporter 1999/4. Oslo: Statistisk sentralbyrå. (In Norwegian only)

Lillegård, Magnar (1994): Prisindekser for boligmarkedet, Rapporter 1994/7. Oslo: Statistisk sentralbyrå. (In Norwegian only)

Pham, Dinh Quang (2004): Sesongjustering for Boligprisindeksen. Notater 2004/29. Oslo: Statistisk sentralbyrå. (In Norwegian only)

7.2. Microdata

Data on dwelling level are stored as text files on Unix.


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