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Statistics on
Income and wealth for households
The statistics provide figures on the level, composition, development and distribution of income and wealth among Norwegian households. They cover all registrated monetary income, both taxable and tax-exempt, as well as wealth and debt. The statistics describe overall trends in income and wealth, as well as their distribution across household types and other population groups.
Selected figures from these statistics
- Indicators of developments in income levels and income and wealth inequalityDownload table as ...Indicators of developments in income levels and income and wealth inequality1
2023 2024 Percentage change 2023 - 2024 2019 - 2024 Median after-tax income for all households, price-adjusted NOK 655 000 676 100 3.2 3.8 Median equivalent income (EU-scale), price-adjusted NOK2 495 400 513 500 3.7 6.5 Share of persons with low income (EU60) (percent)3 10.9 11.1 1.8 -0.9 Share of children under 18 years of age with low income (EU60) (percent)3 11.6 11.4 -1.7 -8.8 Income inequality measured by the Gini coefficient4 0.248 0.248 0.0 -0.8 Income inequality measured by the P90/P10 ratio4 2.8 2.8 0.0 0.0 Average estimated net wealth for households, not price-adjusted NOK 3 742 800 3 890 400 3.9 29.9 Share of total net wealth held by the bottom 50 percent in the wealth distribution (percent) 3.6 3.5 -2.8 94.4 Share of total net wealth held by the top 1 percent in the wealth distribution (percent) 21.8 21.7 -0.5 -6.1 1Persons in student housholds are excluded 2Equivalent income accounts for differences in household size using consumption weights based on the EU equivalence scale. 3The low-income threshold is set at 60 percent of median equivalised income. 4Inequality in equivalised disposable income (EU-scale). The Gini coefficient ranges from 0 (perfect equality) to 1 (maximum inequality). P90/P10 is the ratio between the income level at the 90th percentile (P90) and the income level at the 10th percentile (P10) of the income distribution. Explanation of symbolsDownload table as ... - Income account for households after household type. Average and medianDownload table as ...Income account for households after household type. Average and median1
2024 2023 - 2024 Income from work, average Property income, average Transfers received, average Total income, average After-tax income, average After-tax income, median Change in median after-tax income, adjusted for inflation (percent) Living alone, person under 30 years 413 000 12 700 56 400 482 200 372 700 363 900 3.1 Living alone, person 30-44 years 501 800 21 800 93 400 617 000 459 700 445 300 3.0 Living alone, person 45-66 years 445 700 49 000 176 000 670 700 488 100 437 000 2.9 Living alone, person 67 years and over 36 200 60 200 409 300 505 800 407 100 362 100 3.6 Couple without resident children, oldest person under 30 years 921 400 31 300 70 800 1 023 500 789 700 774 200 3.8 Couple without resident children, oldest person 30-44 years 1 145 100 52 700 100 800 1 298 600 964 000 936 200 3.7 Couple without resident children, oldest person 45-66 years 1 213 200 150 400 287 200 1 650 700 1 161 700 1 043 800 3.5 Couple without resident children, oldest person 67 years and over 191 100 148 500 766 300 1 105 900 863 500 763 200 3.7 Couple with children, youngest child 0-5 years 1 175 500 72 900 269 400 1 517 700 1 132 300 1 067 700 3.8 Couple with children, youngest child 6-17 years 1 535 700 116 800 188 500 1 841 000 1 323 600 1 211 500 3.8 Couple with children, youngest child 18 years and older 1 562 300 158 400 329 600 2 050 400 1 483 000 1 372 700 3.8 Mother/father with children, youngest child 0-5 years 334 800 18 300 295 600 648 700 525 800 506 600 4.2 Mother/father with children, youngest child 6-17 years 563 400 40 100 226 700 830 200 641 100 586 400 4.6 Mother/father with children, youngest child 18 years and older 729 900 63 100 288 300 1 081 400 822 000 762 000 3.8 Two or more-familiy households 942 200 77 200 408 100 1 427 500 1 094 800 994 900 2.7 1Persons in student housholds are excluded. Explanation of symbolsDownload table as ... - Property account for householdsDownload table as ...Property account for households1 2
2024 2023 - 2024 Average for households with different property holdings (NOK) Share of households with different property holdings (per cent) Total (NOK million) Percentage change (NOK million) Estimated real capital 4 489 200 84.6 9 937 819 3.5 Estimated market value primary dwelling 4 576 100 68.9 8 245 797 3.7 Estimated market value secondary dwelling 3 568 900 9.8 913 257 4.1 Gross financial capital 1 873 900 98.7 4 841 252 7.7 Bank deposits 647 800 98.7 1 672 938 5.2 Shares and other securities 3 425 500 23.6 2 111 126 4.4 Share savings account 558 700 32.9 481 562 30.1 Units of mutual funds 302 500 30.0 237 141 15.8 Foreign taxable wealth excl. real properties 516 000 4.7 64 050 -6.3 Estimated gross wealth 5 716 600 98.8 14 779 072 4.9 Debt 2 071 800 84.8 4 598 482 3.9 Study debt 320 200 26.7 223 436 7.7 Estimated net wealth 3 926 400 99.1 10 180 589 5.3 Positive net wealth 4 800 400 83.3 10 463 507 5.2 Negative net wealth -684 800 15.8 -282 918 4.0 Property taxes 63 200 18.7 30 874 8.3 1Student households are not included. 2All wealth items are based on market value or assumed sales value before any tax valuation discount. Figures for bank deposits and foreign taxable wealth excl. real properties were corrected on 12 February 2026. This also affects other wealth measures. Explanation of symbolsDownload table as ... - Percentage share of total estimated net wealth, average net wealth and lowest value in decile for households, by decilesDownload table as ...Percentage share of total estimated net wealth, average net wealth and lowest value in decile for households, by deciles1
2024 2023 - 2024 Lowest value in decile (NOK) Average estimated net wealth (NOK) Share of total net wealth (per cent) Change in share of estimated net wealth (percentage points) Total .. 3 890 400 100.0 0.0 Decile 1 .. -1 031 500 -2.7 0.0 Decile 2 -192 800 -42 900 -0.1 0.0 Decile 3 20 800 159 700 0.4 0.0 Decile 4 390 300 748 600 1.9 -0.1 Decile 5 1 131 000 1 538 100 4.0 0.0 Decile 6 1 955 700 2 406 400 6.2 0.0 Decile 7 2 880 100 3 415 800 8.8 0.0 Decile 8 3 996 700 4 715 300 12.1 0.0 Decile 9 5 543 100 6 787 800 17.4 0.0 Decile 10 8 454 200 20 211 300 51.9 0.1 Top 5 per cent 12 140 200 30 419 900 39.1 0.1 Top 1 per cent 28 250 400 84 551 200 21.7 -0.1 Top 0,1 per cent 133 425 400 402 084 700 10.3 -0.1 1Student households are excluded Explanation of symbolsDownload table as ...
About the statistics
The information under «About the statistics» was last updated 9 February 2026.
The concepts presented here are explained according to how they are used in the statistics. These explanations may differ from the common definitions of the concepts.
Household
A household is regarded as all persons who live permanently in the same dwelling and having common housekeeping. The statistics include only persons in private households. Persons registered as living in institutions are not included.
Student household
A student household is defined as a household where the main income earner is not mainly economically active or in receipt of pensions and benefits, and at least one person within the household receives a loan from the State Educational Loan Fund.
Main income earner
The main income earner is the person in the household who has the highest total income before taxes of the income earners in the household. If there is no income earner in the household, the oldest person is defined as the main income earner.
Total income
Total income is the sum of employee, income from self-employment, property income and transfers received. Assessed tax and other negative transfers are not deducted.
After-tax income
After-tax income is calculated as total income minus assessed tax and negative transfers.
Income from work
Income from work is the sum of employee income and net income from self-employment during the calendar year. As of 2006 sickness and parental benefits is not included.
Income from self-employment
Income received in self-employment jobs. It primarily concerns the profit or loss from unincorporated enterprises.
Property income
Property income is the sum of interest received, share dividends received, realised capital gains (or losses) and other property income received during the calendar year.
For share savings accounts (ASK), capital gains (from the 2017 income year onwards) and dividends (from the 2019 income year onwards) are only recorded as income in the year they are withdrawn from the account.
From the 2024 income year onwards, the allowance for shielding (risk-free return allowance) on realised capital gains has been moved from dividend income to realised capital gains. Furthermore, from the 2024 income year, income from private pension savings (IPA/IPS) is included in “other property income”, whereas it was previously included under occupational pensions (transfers).
Taxable transfers
Taxable transfers include unemployment benefits, old‑age pension, disability benefit, work assessment allowance (AAP), sickness benefits and parental benefits, as well as other taxable transfers from the National Insurance Scheme. In addition, disability benefits from sources other than the National Insurance Scheme, occupational pensions, contractual early retirement pension (AFP), introduction benefit for newly arrived immigrants, and other taxable transfers are included.
Prior to the 2006 income year, sickness and parental benefits were included in income from work. Benefits from the National Insurance Scheme include survivor’s pension for recipients granted this benefit up to and including the 2023 income year, and adjustment allowance from the 2024 income year onwards. From the 2024 income year, income from private pension savings (IPA/IPS) is no longer included in occupational pensions, but is instead classified as “other property income”.
Tax-free transfers
Tax-free transfers consist of child benefits, dwelling support, scholarships, social assistance, basic and attendance benefit and more.
Child support received through private agreements is not registered, and therefore not included in the statistics.
Assessed taxes and negative transfers
This comprises income tax and wealth tax to the central government and municipalities. Examples of negative transfers are pension contributions in employment and paid child support managed by public arrangement.
Estimated real capital
Estimated value of properties, buildings and constructions, possessions, etc.
Market value is used for primary and secondary dwellings, commercial properties, forests and farms.
Tax value is used for other real estate and private and commercial moveable property.
Primary dwelling
A primary dwelling is defined as the dwelling in which the owner has their registered address at the end of the income year. Valuation is based on an estimated market value. The estimated market value is obtained from the tax return and is based on Statistics Norway’s model for estimating housing wealth, which is used by the Norwegian Tax Administration to determine the market value of the dwelling for the relevant income year.
An individual can own only one primary dwelling. In income and wealth statistics, farmhouses on agricultural holdings are not classified as primary dwellings.
Secondary dwelling
A dwelling that a person owns, which is not the primary dwelling. Value is set according to assessed market value. Cabins and holiday properties are not secondary dwellings.
Estimated gross financial capital
Comprises bank deposits, shares, units in mutual funds, share savings accounts, bonds and other securities.
Prior to 2008, discounts were applied to the valuation of shares, mutual funds, primary capital certificates and similar assets. In the wealth statistics for these income years, tax values were therefore used. Between 2008 and 2016, no discounts were applied, and tax values corresponded to estimated market values. From 2017 onwards, discounts in the valuation of financial assets were reintroduced for tax purposes. In the wealth statistics, however, tax values have been adjusted upwards so that the values used correspond to estimated market or sales values.
Estimated gross wealth
Sum of estimated real capital and gross financial capital.
Debt
Household debt comprises liabilities to creditors (such as banks or other private individuals), as well as the household’s share of debt for owners in Building Societies. Household debt corresponds to total liabilities reported in the tax return and tax assessment, adjusted upwards to account for tax valuation discounts.
From the 2017 income year onwards, a proportional reduction was introduced in the total amount of debt deductible for the purpose of wealth tax assessment, where the reduction depends on the composition of the taxpayer’s assets. As a result, from 2017 onwards, debt subject to tax valuation discounts is recorded at market value (i.e. debt before any valuation discounts) in the wealth statistics. Prior to 2017, there was no difference between taxable debt and the market value of debt.
By linking register data from the Norwegian State Educational Loan Fund (Lånekassen) and the Norwegian Debt Register (Gjeldsregisteret AS), the household wealth statistics can separately identify student loan debt and unsecured debt. As the different debt components are sourced from registers with potentially different reporting dates, total debt reported in the tax return minus student loan debt and unsecured debt does not necessarily equal the residual category “other debt”.
Unsecured debt
Unsecured debt includes both interest‑bearing and non‑interest‑bearing balances. Data on unsecured debt are only available from the 2019 income year onwards. The amount of unsecured debt is calculated based on data from Gjeldsregisteret AS as of 31 December in the income year.
Estimated net wealth
Estimated gross wealth minus debt. Pension wealth is not included.
Median income
Median income is the exact income amount that splits a distribution in two equally sized groups, when income is sorted ascending (or descending). The number of persons with income above the median will be the same as the number of persons with income below the median.
Income per consumption unit (equivalent income)
Total household after-tax income divided by the number of consumption units within the household.
The economic needs of a household increase with each additional member, but not proportionally. For example, the need for housing space, electricity and other shared resources will not be three times as high in a household with three members as in a single‑person household, due to economies of scale. Using equivalence scales, each household type in the population is assigned a value that reflects its relative needs. The factors commonly used to assign these values are the number of household members and whether they are adults or children.
Several equivalence scales exist and are used for different purposes. In the income and wealth statistics for households, the EU equivalence scale is most often applied.
Consumption units calculated according to the EU scale
This is the ‘OECD-modified equivalence scale’ which assigns a value of 1 to the household head, of 0.5 to each additional adult member and of 0.3 to each child under the age of 17.
Consumption units calculated according to the OECD scale
In the income and wealth statistics for households, the OECD scale refers to the "old" equaivalence scale used byt he OECD. This equivalence scale assigns a value of 1 to the household head, of 0.7 to each additional adult member and of 0.5 to each child under the age of 17.
Low income threshold
In the income and wealth statistics for households, low‑income thresholds are usually defined as a proportion of the median equivalised after‑tax income. Commonly used thresholds are 50 or 60 per cent of the median after‑tax income per consumption unit.
There is no official low‑income threshold in Norway. Statistics Norway therefore calculates several low‑income thresholds based on the income distribution of the total population. These thresholds are relative to overall income growth and allow comparisons across individuals belonging to different household types.
Low-income group
Persons belonging to a household with annual equivalent income below the low-income threshold.
The Gini coefficient
The Gini coefficient is here used to measure income inequality within a population, either for a specific group or within a geographical unit such as a country or a municipality. It shows how total after‑tax income per consumption unit is distributed within the population. The Gini coefficient ranges from 0 to 1, where 0 indicates that everyone has the same income (perfect equality), while a value of 1 indicates that a single individual receives all income (perfect inequality).
The inequality measure S80/S20
This measure shows the ratio between the average after‑tax income per consumption unit of the 20 per cent of the population with the highest income and the average after‑tax income of the 20 per cent with the lowest income. The ratio indicates how much higher the average income of the richest 20 per cent of the population is compared with that of the lowest‑income 20 per cent.
The inequality measure P90/P10
The P90/P10 inequality measure shows the ratio between after‑tax income per consumption unit for individuals with an income slightly higher than 90 per cent of the population and those with an income slightly lower than 10 per cent of the population. In other words, it compares individuals in the ninth to tenth decile (P90) with those in the first to second decile (P10) of the income distribution. Unlike the S80/S20 measure, P90/P10 is less affected by extremely high or low incomes, as it excludes the incomes of the top and bottom 10 per cent of the population.
Economically active
A person that has income from employment or self-employment that is greater than twice the Basic Amount of the National Insurance Scheme (so-called "G", or "grunnbeløpet"). For the income year 2010 and earlier, persons with income from employment or self-employment greater than the Minimum Pension for single people were regarded as economically active.
This concept differs from the definition “Employed persons” used in other statistics, which defines whether a person is in employment on a certain time.
Single parents
Persons in the household type "mother/father with children aged 0-17 years".
Old-age pensioners
Persons in households where the main income earner, according to the Norwegian Labour and Welfare Administration, receives old age pension from the social security system.
Disability pensioners
Persons in households where the main income earner, according to the Norwegian Labour and Welfare Administration, receives disability pension from the social security system.
Receivers of survivor's benefits
Persons in households where the main income earner, according to the Norwegian Labour and Welfare Administration, receives survivor's benefit (after deceased spouse) from the social security system.
From the 2024 income year onwards, survivor’s pension has been replaced by an adjustment allowance, and no new survivor’s pension recipients are included in the population.
Old-age pensioners with minimum state pension
As of 2021 the definition of receivers of the minimum state pension that the Income and Wealth statistics for Households use is in accordance with the definition used by Norwegian Labour and Welfare Administration.
In the Income and Wealth statistics for Households the number of receivers of retirement pension and the minimum state pension will be fewer than the number the Norwegian Labour and Welfare Administration reports since we only count residents at the close of the year.
Until 2020 receivers of the minimum state pension were defined by persons who received the minimum state pension, or who received a pension supplement.
Receivers of the minimum state pension
Persons who receive the minimum pension level, which is a guaranteed minimum retirement pension payment from the National Insurance Scheme. The definition distinguishes between:
- Old-age pensioners who receive the minimum state pension.
- Disability pensioners who receive the minimum state pension.
- Receivers of minimum level survivor’s benefits
Until 2020 receivers of the minimum state pension were defined as persons who received the minimum state pension, or who received a pension supplement.
Receivers of work assessment allowance
Persons in households where the main income earner is registered with a longstanding illness. Included are persons in receipt of rehabilitation allowances, persons incapable of full labour force participation, but attend labour market schemes, and others. Up until 2005, persons who were incapable of full labour force participation but who attended programmes initiated by the National Insurance Scheme (e.g. school and work placements), and persons who were receiving vocational rehabilitation allowances, were not included in the statistics.
Long-term unemployed
Persons in households where the main income earner has been registered as unemployed for 6 consecutive months or more during the year.
People on social assistance
Persons in households where the main income earner has received social assistance at least once during the year.
Singles
Persons who are the only person in a household.
Immigrants
Persons in households where the main income earner is born abroad by two foreign-born parents (first-generation immigrant).
Norwegian-born to immigrant parents
Persons in households where the main income earner is born in Norway by two foreign-born parents.
Refugees
Persons in households where the main income earner is immigrated to Norway for refuge reasons.
Persons with refugee background
Persons in households where the main income earner is immigrated to Norway for refuge reasons or immigrated family members of these.
Age
Age (number of years) at the end of the year.
Socioeconomic status
Socioeconomic status is described by type of economic activity. The economically active population, which mainly receive their income from working, is divided into self-employed and employees. If income from self-employment is greater than income from employment, the person is classified as self-employed, and vice versa.
We have the following socio-economic groups:
Working
- Self-employed in agriculture, forestry and fishing
- Self-employed in other industries.
- Employee
Non-working
- Pensioners and National Insurance recipients
- Other non-working
Income sources not included in the income and wealth statistics
After-tax income comprises the sum of income from work, property income and transfers, where assessed taxes and negative transfers are deducted. This way of defining income is in accordance with the practical definition recommended in the Canberra report (United Nations Economic Commission for Europe 2011).
The income statistics cover most of the various monetary income sources. Due to lack of information, the following elements are not included in the statistics although they affect the income level.
- The value of public services, such as public health care and education
- The net value of unpaid domestic services. This include unpaid housework, child care and goods produced for own consumption
- The net value of owner-occupied housing services.
- The net value of services from household consumer durables
- Income withheld from taxation or gained from criminal activities
- Child support received through private agreements
- Rental income when renting out less than 50 per cent of owner-occupied housing
- Municipal subsidy schemes for housing and cash benefits for child care
- Local property taxes are not deducted when estimating after-tax income due to lack of information
- Interest payments are not deducted from after-tax income, although data on this is available. This is done as a rough compensation for not including the value of owner-occupied housing services in the income.
Types of household are in accordance with standard classifications.
Name: Income and wealth for households
Topic: Income and consumption
Division for Income and social welfare statistics
National level, counties, municipalities, urban districts in the four largest cities and statistical tracts.
Annually. The statistics are released in the last quarter in the year after the statistical year.
Income data is used in Eurostat's structural indicators on low income and income distribution (EU SILC). Micro data for selected years is also included in the databases Luxembourg Income Study (LIS) and Luxembourg Wealth Study (LWS). Income data is also included in OECD's Income Distribution Database.
Collected and revised data are stored securely by Statistics Norway in compliance with applicable legislation on data processing.
Statistics Norway can grant access to the source data (de-identified or anonymised microdata) on which the statistics are based, for researchers and public authorities for the purposes of preparing statistical results and analyses. Access can be granted upon application and subject to conditions. Refer to the details about this at Access to data from Statistics Norway.
The purpose of the statistics is to quantify the economic resources the households have available for saving and consumption. This is a basis for information about essential sides of the state and development of living conditions and welfare in the society, such as:
- Types of income and the size of these
- Wealth and debt – sizes and types
- How income and wealth is distributed between households
This gives an opportunity to measure economic inequality, estimate the extent of low income, rate of debt, economic activity and other conditions, and study how this varies between types of households, population groups, regions etc.
The Income Distribution Survey was conducted annually from 1986 to 2004 based on a representative sample survey. Information on the household composition was collected from various Living Condition Surveys and Household Budget Surveys. Up until 1992, the income data was obtained in the form of paper forms from the local tax offices. In addition, tax-free transfers were obtained electronically from other government agencies. Beginning with the survey for the 1993 income year, it was possible to obtain all income data from the personal tax return in electronic form. From 2005 we have also established household composition by using registers. This means that we are now able to produce a totally register-based household income statistics
The main users are the Ministry of Finance, Ministry of Labour and Social Affairs, Ministry of Children and Families, the Norwegian Directorate of Health, the Norwegian Labour and Welfare Administration, local and regional authorities and research institutes in the areas of household economics, tax research and living conditions in general.
The tax model “LOTTE”, which is operated by Statistics Norway and is used for simulation of taxes and in tax research is updated annually with data from the Income and wealth statistics for households.
The data sources are very detailed and are therefore capable of providing other arrangements and allocations of statistics than those that are published by Statistics Norway.
No external users have access to statistics before they are released at 8 a.m. on ssb.no after at least three months’ advance notice in the release calendar. This is one of the most important principles in Statistics Norway for ensuring the equal treatment of users.
Tax statistics for personal tax payers is an important data source for the statistics on income and wealth for households. The tax statistics include data from all the records in the tax return and is obtained for all persons residing in the country. The statistics have been available as total census based on registers from the year 1993 and on.
The statistics are developed, produced and disseminated pursuant to Act no. 32 of 21 June 2019 relating to official statistics and Statistics Norway (the Statistics Act).
Not relevant.
The statistics cover all persons resident in the country who also belonged to a private household as of 31 December in the income year. This implies that persons registered as permanently residing in institutions are not included. From 2013 onwards, residents who are studying abroad are also excluded from private households.
The register‑based income and wealth statistics have been a full census from 2004 onwards. Households are derived from thestatistics on families and households. A household is defined as persons who live together on a daily basis and share a common economy. Households are constructed by separating students living away from home from the parental household. Sample surveys indicate that fewer than 10 per cent of the country’s approximately 200,000 students actually live in the same household as their parents. In addition, other information is used to identify more cohabiting couples as belonging to the same household, and data from NAV are used to identify additional residents in institutions.
Income data is received by linking different administrative registers and statistical data sources for the whole population as of 31st of December of the income year. Income and biographical data is collected from the following sources:
- Data from tax returns (wages and salaries, self-employment income, pensions etc.)
- The Tax Register (taxes)
- The a-ordning (unemployment benefit, various tax-free transfers)
- Norwegian Labour and Welfare Administration (family allowances, basic and additional amounts, cash benefit etc.)
- KOSTRA (social assistance)
- State Educational Loan Fund -Lånekassen (loans to students, scholarships)
- Gjeldsregisteret AS (unsecured debt)
- The Debt Settlement Register – Brønnøysund Register Centre - Gjeldsordningsregisteret (individuals under a public debt settlement scheme)
- Education statistics and household statistics from Statistics Norway (highest level of completed education etc.)
- Sample survey in the period 1986-2004. From 2004 totally census-based.
Data are collected from various administrative registers.
Consistency controls are undertaken by comparing information from different sources.
The population of the Income Distribution Survey (1986-2004) was weighted by the use of a calibration program. This method of estimation permits the population to show the same aggregates familiar from the register statistics (for the population) for selected variables. This applies to the different personal incomes and net wealth.
Not relevant.
Interviewers and everyone who works at Statistics Norway have a duty of confidentiality. Statistics Norway has its own data protection officer.
Statistics Norway does not publish figures where there is a risk of identifying individual data about persons or households.
The surpression method is used in this statistics to ensure this, by supressing any combination that would display 11 or fewer observations.
More information can be found on Statistics Norway’s website under Methods in official statistics, in the ‘Confidentiality’ section.
The Income and wealth statistics has gone through several significant changes through the years. This is due to changes in the income concept, as a result of changes in the tax system and access to new income components from registers.
The estimation of household wealth has also changed over the years, according to changing tax rules and available data and methods for estimating market value for various wealth components. From 2010 and on, for example, Statistics Norway has been able to estimate market value for primary and secondary dwellings in Norway.
Some data collection and processing errors are unavoidable. These include coding errors, revision errors, data processing errors, etc. Comprehensive efforts have been made to minimize these errors, and we regard these types of errors to be relatively insignificant.
Sources of error and uncertainty before 2005
From and including the income year 2005, these statistics are based on a total census and will not be affected by variance and bias. For previous years with survey-based statistics, the following is of relevance:
All sample surveys are subject to a certain amount of uncertainty. In general; the fewer observations the more uncertain the results. Results based on less than 20 observations are therefore not published.
Groups based on relatively few observations will be very strongly influenced by extreme observations, i.e. observations that deviate greatly from the average. In this statistics, extreme observations in most cases are included, but an attempt has been made to reduce the effect of such observations by adjustments (reduction) of the household weights.
Bias can occur when the distribution between certain groups in the sample is not the same as the corresponding distribution in the total population. Sample bias of this type can occur through non-response. Most of the data for the Income Distribution Survey was obtained from administrative registers. Non-response is not a problem for this part of the material. The household composition was based on interviews, where there will always be non-response. Non-response is adjusted by replacing household data with data on family composition from registers.
A revision is a planned change to figures that have already been published, for example when releasing final figures as a follow-up to published preliminary figures. See also Statistics Norway’s principles for revisions. Not relevant here.