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/en/befolkning/statistikker/folkfram/arkiv
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statistikk
2012-06-20T10:00:00.000Z
Population;Population
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Population projections2012-2100

Content

About the statistics

Definitions

Name and topic

Name: Population projections
Topic: Population

Next release

Responsible division

Research department, Unit for Social and Demographic Research

Definitions of the main concepts and variables

A population projection is an estimate of the future size and composition of a population, given certain assumptions of future fertility, life expectancy, domestic migration, immigration and emigration. The term projection is used for any estimate of the future population, also less likely ones. A prognosis or forecast is an estimate of the most probable future population size and composition.

 

Statistics Norway publishes several projections, but the MMMM alternative which assumes the medium level for each component is what we assume to be most plausible and to the greatest extent can be regarded as a population forecast or prognosis.

The variables and terms used in the population projections are described in the projections' report (see link below, 'Relevant documentation').

Standard classifications

Not relevant.

Administrative information

Regional level

The lowest regional levels for the population projections are municipalities (city districts for Oslo).

Frequency and timeliness

The population projections are published biennially.

International reporting

Statistics Norway reports projections to Eurostat and the United Nations, among others.

Microdata

The population projections utilize aggregated individual level data on population size, births, deaths and migration from Statistics Norway’s population statistics. The results from the projections are stored in the StatBank at Statistics Norway and as separate files. Aggregated data may be downloaded electronically from the StatBank.

Background

Background and purpose

The population projections aim at informing planning and public debate on population issues.

SSB has produced population projections regularly since the 1950s. Previous population projections can be found here, and in the StatBank.

Users and applications

The most important users of Statistics Norway's population projections are public and private planning bodies at the municipal, county and central government levels, as well as journalists, researchers, politicians and the general public. The projections are also used internally in SSB, for example as input in macroeconomic models.

Equal treatment of users

Not relevant

Coherence with other statistics

The population projections are published in accordance with international standards. The Norwegian figures are more detailed (regional level, immigration category, country group and period of residence) than what is commonly published from most other countries.

Legal authority

There are no specific rules regulating the population projections, but the production process of the projections is based in the Norwegian Statistics Act of 1989.

EEA reference

Although there is no separate EU regulation of this field, a collaboration exists between Norway and Eurostat. Eurostat produces population projections for the EU and Norway on a regular basis. These projections differ from those produced by Statistics Norway.

Production

Population

To project the population, assumptions are needed on future fertility, mortality, internal migration and international migration. After the assumptions are made, the Norwegian population is projected using the two cohort component models BEFINN and BEFREG.

The methods used are further described in the projections' report (see link below, 'Relevant documentation').

Data sources and sampling

The population projections utilize aggregated individual level data on population size, births, deaths and migration from Statistics Norway’s population statistics. We use data categorized by age, sex, immigrant background and country group of origin for 1 January each year, in addition to figures on births, deaths, domestic migration, immigration and emigration by age, sex and municipality/city district.

No samples are used. The projections utilize the whole population in estimations.

The methods used in the population projections are further described in the projections' report (see link below, 'Relevant documentation').

Collection of data, editing and estimations

No data are collected specifically for the purpose of making population projections.

Seasonal adjustment

Not relevant

Confidentiality

Not relevant.

Comparability over time and space

At a national level, the various versions of the population projections are comparable over time. The projections are comparable also at the regional level, apart from in situations where municipalities have been merged or divided.

Country groups are not entirely comparable over time, since the definition and the number of groups have varied.

In comparing results from the population projections to the general population statistics at Statistics Norway, two main differences stand out:

1)       The projection models project the population from 1 January one year to 1 January the year after. This means that individuals who move several times during one year, only contribute with one move, or with zero moves if the person reside in the same municipality at the beginning and the end of the year. Similarly applies for moves between Norway and other countries. Consequently, somewhat fewer migrations are used in the population projections compared to the numbers that are published in the general population statistics.

2)       The age definitions are not the same in the projections and the general population statistics. Whereas the general population statistics use age at time of event (e.g. birth, death or migration), the projections use age at the end of the year. This means that the age-specific ratios and probabilities used in the projections – as well as the life expectancy figures – may differ slightly from what is published in the population statistics.

 

Accuracy and reliability

Sources of error and uncertainty

There is a marked uncertainty about whether the assumptions used in making the population projections will accurately reflect future demographic trends.  Over the past decade, future immigration has proven to be the most difficult component to project. This is also likely to be the case in the years ahead. Fertility, mortality and internal migration can also be very different from what was projected.

Models are simplifications of reality, and as such may only capture a few key mechanisms. This means that there are a multitude of other conditions that will affect population development which are not considered.

Errors in the population statistics system are usually modest in Norway and play a minor role in the projections

In summary, the uncertainty increases with time, and the percent wise errors are typically greatest for small municipalities. For more information, see link below, ‘Relevant documentation’.

Revision

Not relevant