About the statistics

1. Administrative Information

This version is last edited 03.07.2002.

1.1. Name

Imprisonments

1.2. Subject Group

03.05. Crime and Justice

1.3. Frequency

Annual

1.4. Regional Level

Statistics on the national level (Norway)

1.5. Responsible Division

Division for Social Welfare Statistics (350)

1.6. Authority

The Statistics Act of June 16^th 1989, Section 3-2

1.7. EU Regulation

None

2. Background and Purpose

2.1. Purpose and History

Statistics Norway aims, through its imprisonment statistics, to provide annual data on the prison population, as well as on the entries to and the departures from Norwegian penal institutions. The organization has, since 1960, provided statistics on imprisonments and releases from Norwegian prisons. The Ministry of Justice provided some imprisonment statistics prior to 1960, the oldest of which dates back to 1875.

Statistics Norway expanded its imprisonment statistics in 1966, by including those who were imprisoned for failure to pay a fine and those held in custody. Until 1977, these statistics were based on complete individual level data with fairly detailed information on each unit. In the following thirteen years, from 1978 to 1990, the imprisonment statistics was based on aggregate level data from the Ministry of Justice, which only included data on the individuals' sex, type of sanction, and penal institution. Statistics Norway went back to using individual level data with more detailed information on each unit in 1991.

2.2. Users and Applications

The users of the imprisonment statistics are students, researchers, the Ministry of Justice, the National Bureau of Investigation (KRIPOS), the Public Prosecutor's office, the media, and other interested citizens.

3. Statistics production

3.1. Population

The statistics include three types of units: the prison population in Norwegian penal institutions on January 1^st every year, as well as the entries to and the departures from these institutions each year.

3.2 Data Sources

The data comes from the Norwegian Central Penal Register (SSP) and is supplemented with some data from the Central Computer System for the Prison Service (KOMPIS). The Ministry of Justice owns both registers.

3.3. Sampling

3.4. Collection of Data

Statistics Norway collects the individual level data from SSP in a data-file. It also gets summary statistics on the number of people serving prison time for not paying a fine, and on the total number of prison days spent in Norwegian prisons in the course of a year, from KOMPIS.

3.5. Response Burden

3.6. Control and Revision

3.7. Analysis

4. Concepts, Variables and Classification

4.1. Definition of the Main Concepts

There are three types of units in the imprisonment statistics, namely the prison population at the start of each year, as well as each individual entry to and departure from Norwegian penal institutions. A person may enter and depart prison more than once in a year, and will thus appear in the imprisonment statistics the corresponding number of times.

An entry to a penal institution is the occurrence of an imprisonment to custody, for serving a sentence, or a re-imprisonment after failure to return from provisional leave or after an escape.

A departure from a penal institution is the occurrence of an unconditional permanent discharge, a conditional discharge, an escape, a failure to return after a provisional leave, an intermission in the sentence, or the death of an inmate.

4.2. Definition of the Main Variables

Main offence: if an imprisonment stems from more than one offence, the main offence is the offence that may, according to the law, lead to the longest prison sentence.

Age: On January 1^st, for the prison population, or on the date of the entry or departure from prison.

Sanction: Prison sentence, custody, security detention, or imprisonment for not paying a fine.

4.3. Standard Classifications

5. Sources of Error and Uncertainty

5.1. Collection and Processing Errors

5.2. Sampling Errors

5.3. Non-Sampling Errors

At the determination of which offence is to be considered as the "main offence" (see section 4.2), one only employs the general guidelines of Norwegian law. This may, in some instances, mean that the "main offence" is something other than the most serious crime a person has committed.

6. Comparability and Coherence

6.1. Spatial Comparability and Comparability over Time

The main data on the prison population, the entries to and the departures from prison may be compared over time. You can also compare the distributions in terms of sex, age and type of sanction over time. The categories of the type of offence have changed somewhat over the years, but most of them can be compared from one year to another. From 1993 onwards, the imprisonment statistics does not include any regional distributions, so spatial comparison in that sense is not possible.

6.2. Coherence with other Types of Statistics

Statistics Norway publishes four types of crime statistics, which are coherent in terms of variables and categories. They are, in addition to imprisonment statistics, "offences reported to the police", "offences investigated", and "sanctions".

7. Availability

7.1. Internet Address

http://www.ssb.no/fengsling_en/

7.2. Language

Norwegian (Bokmål) and English

7.3. Publications

The imprisonment statistics is published every year on the Internet and in the annual publication series "The Official Statistics of Norway" (NOS), in "NOS - Crime Statistics".

The Statistical Yearbook of Norway

Social Survey 2000

7.4. Storing and Use of Basic Material

Statistics Norway stores the annual files as raw data, and to some extent as adapted or modified files.