This is a presentation I gave to the SAS Professionals Convention 2012. It is about the National Performance Framework and how I have used SAS to inform a National Indicator in this framework. Re-offending is a continuing problem and it is “the key measure of the criminal justice system’s success in England and Wales” (a quote by the National Audit Office in a briefing to the House of Commons Justice Committee, Feb 2012). Reoffending has the obvious social implications to its victims in certain neighbourhoods, but it is also costly in terms of the police, courts, legal aid, prisons and social work. Reducing re-offending is an important policy area and it has its own work programme in the Scottish Government. My particular interest is in the reconviction rates of offenders in Scotland.

1. make connections • share ideas • be inspired
Using SAS to Inform a Performance
Indicator on Scotland Performs: A
Study of Reconvictions
Ian Morton, Statistician,
Justice Analytical Services, Scottish Government
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2. Contents
o Scotland Performs
o Technical Notes and Reconvictions
o Baseline, Progress and Targets
o Stakeholders
o National Results
o Local Level Performance
o The good, the bad and the ugly
o Summary
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3. Scotland Performs
 Measures and
reports on
progress of
government in
Scotland
(http://www.scotla
nd.gov.uk/About/s
cotPerforms)
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4. Purpose Targets, National Outcomes & Indicators
o Scotland Performs is tracked by …
o 7 purpose targets (e.g. Solidarity: To increase overall income and the
proportion of income earned by the three lowest income deciles as a group
by 2017),
o 16 National Outcomes (e.g. We live our lives safe from crime, disorder and
danger http://www.scotland.gov.uk/About/scotPerforms/outcome),
o 50 National Indicators (e.g. reduce reconviction rates
http://www.scotland.gov.uk/About/scotPerforms/indicator)
o One such indicator is the reconviction rate of offenders
(http://www.scotland.gov.uk/About/scotPerforms/indicator/reconviction)
o Current Status: The reconviction frequency rate decreased by 1.8
reconvictions per 100 offenders, from 59.7 in the baseline year of 2006-07 to
57.9 in 2008-09.
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5. Reconvictions Technical Note
o Each indicator has a technical note …
o Reconvictions
http://www.scotland.gov.uk/About/scotPerforms/TechNotes/reconvictions
o Explains:
o Baseline year and magnitude of measure
o How we measure progress
o If there is a target
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6. Baseline
o A baseline year of 2006-07 was chosen because this related to the
financial year coinciding with the previous government
o Baseline reconviction frequency rate (59.7 reconvictions for every 100
offenders)
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7. Progress
o Progression seen through a 'direction of travel' arrow shows
o improving (↓ for reconviction), worsening (↑) or maintaining (↔).
o How do we choose this ? Confidence Intervals:
o Parametric model (Poisson) or Non-parametric model (Bootstrap).
o References:
o [Poisson] Spiegelhalter D (2009) A predictable pattern of murder
http://understandinguncertainty.org/node/200
o [Bootstrap] Miller, D.P. (2004) Bootstrap 101: Obtain Robust Confidence
Intervals For Any Statistic SUGI 29 Proceedings Paper 193-29
Montréal, Canada May 9-12, 2004
(http://www2.sas.com/proceedings/sugi29/193-29.pdf)
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8. Targets
o Previous target
o Baseline of 2004-05, Reduce reconvictions rates by 2% by 2011
o Historically the previous target was chosen because it looked plausible
and sounded stretching
o Use survival analysis – where survival time is the number of
months to reconviction for those convicted previously
o References:
o Allison P (1995) Survival Analysis Using the SAS System, SAS
Institute.
o Fox J (2006) Introduction to Survival Analysis
(http://socserv.mcmaster.ca/jfox/Courses/soc761/survival-analysis.pdf)
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9. Stakeholders
o Community Justice Authorities
o Local authorities
o Scottish Prison Service
o Scottish Police Forces
o Scottish Court Service
o Risk Management Authority
o Parole Board for Scotland
o Crown Office and Procurator Fiscal Service
o Health Boards
o Victim Support
o Third Sector Partners
o COSLA
o Association of Directors of Social Work
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10. National Results
o Current Status: The reconviction frequency rate decreased
by 1.8 reconvictions per 100 offenders, from 59.7 in the
baseline year of 2006-07 to 57.9 in 2008-09.
o Confidence Intervals for 2006-07
o Parametric model [59.0,60.4]
o Non-parametric model [58.7,60.7]
o Suggests +-1 = maintaining
o Conclusion for 2008-09: Performance Improving
o Target (Survival Analysis: not completed yet)
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11. Local Level Performance
o The Management of Offenders etc. (Scotland) Act 2005
established provisions for 8 local CJAs.
o Established to provide planning, manage performance and to
report on performance of the 32 local authorities.
o Aim is to target services to reduce reoffending and to ensure
close co-operation between community and prison services
to aid the rehabilitation of offenders.
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12. The Bad and The Ugly
o A league table ignores sample size and uncertainty
o Ref: Bird et al (2005) Performance indicators: good, bad, and ugly J R Stat
Soc A 168, Part 1, pp. 1–27
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13. The Good
o Reference: Spiegelhalter, D. J. (2005) Funnel plots for comparing institutional performance
Statistics in Medicine 24 1185-1202.
o Can remove offender mix using logistic regression (see bulletin ref on next slide): Allison, P.
D. (1999) Logistic Regression Using the SAS System SAS Institute and Wiley, North Carolina.
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14. Further Information
o If you want to delve deeper see the latest bulletin – pages 15 and 16
(http://www.scotland.gov.uk/Publications/2011/08/29151240/0)
o Or see my slideshows / papers on Linkedin
o http://uk.linkedin.com/in/idmorton
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15. Summary
o Scotland Performs measures and reports on progress of government in
Scotland.
o Described the use of SAS to provide statistical information for Scotland
Performs.
Key Facts
o Recorded crime in Scotland is at its lowest level since 1976 and is down by
23% since 2006-07.
o One year reconviction rates are at their lowest point in the past 12 years, with
31% of the 2008-09 cohort reconvicted within a year.
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16. make connections • share ideas • be inspired
Questions
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