International Journal on Criminology Volume 1, Number 1, Fall 2013 | Page 50

Demographic Analysis of the Penal System
each section in detention centers. During the "2004–2012" period, the maximum was
noted on June 1, 2004 with a number of surplus detainees of 16,086. The minimum was
noted on August 1, 2006, with a surplus number of detainees of 7,717. The number of
detainees sleeping on a mat on the floor is 639 as of January 1, 2013.
Annual entries into prison and indicator of the average duration of time in prison
In 2011, the increase in the average number of persons in prison was linked to an increase
in the number of entries into prison, which was 6.4% higher compared to 2010 (88,058
versus 82,725). The indicator of the average duration of time spent in prison remained
stable, but at a record level (9.8 months).
Field: The whole of France
2006 2007 2008 2009 2010 2011
Annual entries into
prison (E) 86,594 90,270 89,054 84,355 82,725 88,058
Average population
in prison (P) (i) 59,938 63,268 66,716 67,362 67,317 71,755
Average duration in
prison (d, in months)
(ii)
8.3 m 8.4 m 9.0 m 9.6 m 9.8 m 9.8 m
(i) Average of the numbers on the first day of each month.
(ii) This indicator of average time spent in prison (d) is calculated according to the
equation P = E × d (where P is the average number throughout the year and E is the
number of committals to prison in the year), an equation based on the hypothesis of
stationarity (constant annual committals to prison, with identical release schedules for all
imprisoned cohorts).
About the Author
Pierre V. Tournier serves as Research Director at CNRS, 20th Century Social History
Center (Université Paris 1),://pierre-victortournier.blogspot.fr/
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