Lost your Password?
Click Here
Don't have an account?
Register Here
Welcome to the EuroPris Knowledge Management System. The table below shows questions and responses from European National Agencies. Select a question for more information or use the filters on the left to narrow down questions based on Agency or Category.
Want to ask a question? Please read our guidance information found here: Submitting a KMS Question
← Back Search KMSThis content is only available to registered members of EuroPris.
Introduction: The Directorate General of Prison Services of Catalonia would like to know which is the specific model used by other penitentiary administrations for forecasting future inmate population. At present the Catalan Prison Services are auditing their own model of predicting prison population, which is ARIMA (autoregressive integrated moving average model). The information gathered about the models used by other administrations will be very helpful in order compare and refine their own forecasting model with the aim of improving policy development, capacity planning and resource allocation.
We don't have any of those tools...
Which are the factors taken into account when making the projection? What is the forecast horizon? What is the forecast periodicity? Which are the percentage errors between projected prison population and the actual prison population figures?None
Which are the factors taken into account when making the projection?n/a
What is the forecast horizon?n/a
What is the forecast periodicity?n/a
Which are the percentage errors between projected prison population and the actual prison population figures?n/a
This content is only available to registered members of EuroPris.
Several modells are used: ARIMA, Winter, Regression
Which are the factors taken into account when making the projection?monthly inflow inmates to prison and probation Average number of pre-trail detainees (monthly) Average number of prison population (monthly) Average number of pobation population (monthly)
What is the forecast horizon?4 years
What is the forecast periodicity?Every year
Which are the percentage errors between projected prison population and the actual prison population figures?First year approximately 2-3 percent
In Croatian Prison System we don’t use any specific model for forecasting future inmate population.
Which are the factors taken into account when making the projection?n/a
What is the forecast horizon?n/a
What is the forecast periodicity?n/a
Which are the percentage errors between projected prison population and the actual prison population figures?n/a
The Corps of Prison and Court Guard uses for forecasting future inmate population its own non-standardized methodology based on the average daily increase or decrease of inmates for the period of the previous five years.
Which are the factors taken into account when making the projection?The average daily increase or decrease of inmates for the calendar year – sum of the gap of the number of inmates on the individual days of the calendar year.
What is the forecast horizon?Usually the period of 5 years.
What is the forecast periodicity?The forecast is usually updated each calendar year in January.
Which are the percentage errors between projected prison population and the actual prison population figures?The percentage error between the projected prison population and the actual population figures in the last 7 years was 0,36 % to 1 %. The year 2013 was exceptional, at that time the error reached 13,2%. However, this data was influenced by the unexpected amnesty of the President of the Slovak Republic when 798 prisoners were released.
To estimate the future prison population we use an input-output model based on statistiscal co-variation between a number of parameters.
Which are the factors taken into account when making the projection?Parameters used for forecasts: • the development in the number of reported criminal offences reported to the police, especially offences, which traditionally lead to unsuspended prison sentences, i.e. homicide, assault, drug offences, sexual offences and robbery • the number of sentences and the length of the sentences, which are reported to the Department of Prisons and Probation. • the development in the number of convicted waiting for serving a sentence, • the development in the number of persons convicted to community services, • the development in placements in institutions outside prison according to art. § 78 in order of the Execution of Sentences (for instance young people placed in institutions which are established as an alternative to prisons), • the development in refusals of obtaining a release on parole, • the development in the average time spent in prison grouped by type of offences, • the legal and political development • the development in the use of remand custody (number of remanded prisoners and the length of imprisonment in remand custody.
What is the forecast horizon?The Department of Prisons and Probation elaborates an annual forecast, which covers one year ahead.
What is the forecast periodicity?Yearly forecasts
Which are the percentage errors between projected prison population and the actual prison population figures?Statistically an uncertainty of 2.7 percent could be expected. . In 2017 the deviation between the forecasted prison population and the actual prison population was 1.6 percent.
Northern Ireland Prison Population Projections are based on the historical linear trend with added seasonality factors built in to produce monthly forecasts if required, and estimate min and max figures.
Which are the factors taken into account when making the projection?Historical Trends Seasonality factors Future Policy which may affect the prison population in the future
What is the forecast horizon?5 – 10 years
What is the forecast periodicity?Annual
Which are the percentage errors between projected prison population and the actual prison population figures?These are not available
In the past we produced long-term projections based on a combined forecasting method using linear regression to predict prison receptions, and seasonal exponential smoothing to account for seasonal patterns in receptions. ARIMA was adopted following a 2008 review to improve the accuracy of short-term projections, and to end the reliance solely on projecting forward long term historical trends. More recently a crime-based prison population model has been developed to explain the underlying reasons for changes in the prison population (e.g. in terms of changes in crime, clear-up rates, sentencing, etc) though this has not, to date, been used for forecasting.
Which are the factors taken into account when making the projection?ARIMA projections are based on historical trends in average monthly prison population.
What is the forecast horizon?12 months ahead.
What is the forecast periodicity?Monthly.
Which are the percentage errors between projected prison population and the actual prison population figures?The purpose of the ARIMA projections run is to indicate the likely trends in population should current trends continue, and the possible range of uncertainty (based on 95% confidence intervals). As such, the difference between the specific figures for the projected and actual population have not routinely been recorded. The accuracy of the previous longer-term projections was assessed in 2015: https://www.gov.scot/Publications/2015/12/5123/21 Earlier projections have proved to be increasingly inaccurate, as the previous long-term trend of a rising population was reversed from 2011 onwards.
No specific forecasting models are used due to a relatively small number of prison population
Which are the factors taken into account when making the projection?Actual number of inmates, trends in the amount, amendments to legal regulations which may have influence on the number of prison population, national economic situation, etc.
What is the forecast horizon?one to three years
What is the forecast periodicity?Not less than twice a year
Which are the percentage errors between projected prison population and the actual prison population figures?approx. 5%
No mathematical forecasting model is used. Forecasts are based on educated expert opinions.
Which are the factors taken into account when making the projection?-
What is the forecast horizon?-
What is the forecast periodicity?-
Which are the percentage errors between projected prison population and the actual prison population figures?-
This content is only available to registered members of EuroPris.