The Quantification of Prison Population Projections

Published: January 2012

This article examines projections, or statistical forecasts, of prison populations from a social perspective, treating them as social actors in their own right. Linear regression – the almost universal foundation of prison population projections – is in simple terms the act of drawing a straight line through the data at an angle which best ‘fits’ the observed data, that is, what has already happened. In this way, population projections work as a narrative device, finding order, patterns and normality to tell a story of growth or decline. A hidden feature of this technology of knowing the future is the imposition of narrative coherence on the past. However, a review of the past projections reveals their own inherent instability, volatility and chronic inaccuracy. The paper suggests that the accuracy of prison population projections is less important than their power to create a sense of control and legitimacy to penal policy makers. The paper concludes by characterizing forecasts as an act of imagination and argues for counter-discourses and imaginaries that might balance the power of the numbers.

Authors / Editors

Prof Sarah Armstrong

University of Glasgow

Research Themes

Evidence, Statistics and Trends

Research Methods and Criminological Theory

Criminal Justice Process and Institutions