skip navigation


Register for Latest Research

Stay Informed
Register with NCJRS to receive NCJRS's biweekly e-newsletter JUSTINFO and additional periodic emails from NCJRS and the NCJRS federal sponsors that highlight the latest research published or sponsored by the Office of Justice Programs.

NCJRS Abstract

The document referenced below is part of the NCJRS Virtual Library collection. To conduct further searches of the collection, visit the Virtual Library. See the Obtain Documents page for direction on how to access resources online, via mail, through interlibrary loans, or in a local library.


NCJ Number: 221978 Find in a Library
Title: Estimating Mean Length of Stay in Prison: Methods and Applications
Journal: Journal of Quantitative Criminology  Volume:24  Issue:1  Dated:March 2008  Pages:33-49
Author(s): Evelyn J. Patterson; Samuel H. Preston
Date Published: March 2008
Page Count: 17
Type: Report (Study/Research)
Format: Article
Language: English
Country: United States of America
Annotation: This paper examines various approaches for studying the mean length of stay in prison, providing a systematic analysis of existing measures and developing two new methods for estimating mean length of stay in prison.
Abstract: The authors first describe the best method for estimating mean length of stay, i.e., the life table, and then profile three other estimation methods, each of which relies on the assumption of a stationary population. They show what biases result in these measures when a population is not stationary and develop a method for correcting the biases in two of the three cases. The paper then demonstrates the performance of the four existing methods and two improved methods in populations that are not stationary. One set of such populations is termed "stable" populations in terms of demographics. Next, the authors use population simulation, which allows the imposition of shocks stemming from growth or decline in prison admissions and in changes in the length of stay inside prison. Both of these approaches permit the assessment of the sensitivity of the estimates to violation of assumptions and to error in data. The paper concludes with recommendations about the measures to be used for future examination of length of stay in prison. 7 tables, 27 references, and appended sources and processing of data and derivations
Main Term(s): Criminology
Index Term(s): Estimating methods; Incarceration; Research methods; Sentencing/Sanctions
To cite this abstract, use the following link:

*A link to the full-text document is provided whenever possible. For documents not available online, a link to the publisher's website is provided. Tell us how you use the NCJRS Library and Abstracts Database - send us your feedback.