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Predicting the Final CRC Re-Offending Rates

Predicting the Final CRC Reoffending Rates

Predicting the Final CRC Reoffending Rates

On October 26th 2017, the Ministry of Justice will publish the first Transforming Reoffending proven reoffending rates. These will describe the October to December 2015 cohort’s proven reoffending rate and compare this to a 2011 baseline rate (go here for an explanation). If a Community Rehabilitation Company (CRC) does better than the baseline rate they will be paid a bonus. In this blog I am using descriptive statistics to present a prediction of what the final rates will be.

England and Wales Reoffending Rate

Over the last year the Ministry of Justice has published this cohort’s, and each subsequent cohort’s, reoffending rate every 3 months. The national reoffending rate across all CRCs is described in the figure below (these figures are adjusted for differences in likelihood of reoffending across cohorts). Each bar represents a different cohort and gaps exist where the data have not yet been published.

 

Ministry of Justice Proven Reoffending Quarterly Statistics

Source: Ministry of Justice Proven Reoffending Quarterly Statistics

Definition: Months after commencement is the minimum number of months after commencement for an offender in the October 2015 to December 2015 cohort. However in the figures published, the follow up period varies depending on when within those 3 months the offender started.

 

The results are similar across the cohorts. After 8 months, 33% of offenders will have reoffended, and then 39% after 11 months, 42% after 14 months and 43% after 17 months. Most offending will occur within the first 8 months and the subsequent increases are smaller each time.

Predicting the final October to December 2015 rate

In order to predict the final reoffending rate at 18 months I need to estimate the trend. There are different options for doing this, and I will explain in a forthcoming blog how I selected the appropriate method. However, the trend I calculated for the October to December 2015 cohort is presented in the figure below.

 

Predicting the final October to December 2015 rate

Source: Ministry of Justice Proven Reoffending Quarterly Statistics

Definition: Months after commencement is the minimum number of months after commencement for an offender in the October 2015 to December 2015 cohort. However in the figures published, the follow up period varies depending on when within those 3 months the offender started.

 

The blue squares describe the published England and Wales reoffending rates, the red line is the fitted trend, and the red dot describes the predicted reoffending rate after 18 months. The predicted reoffending rate was just under 45% using this method. The selected reoffending trend is a curve to represent the reduction in the rate of increase as time progresses. Even from the limited data released, the curve shows an expected rapid increase in the first months after the start of an order or licence, but over time this increase is not sustained.  This trend is consistent with other research we have conducted using more detailed data.

October to December 2015 CRC results

I extended the same analysis to individual CRCs. When the final results are published, a CRC’s reoffending rate will be compared to a 2011 baseline rate. Since individual baseline rates for each CRC’s baseline have not been published, I cannot anticipate that analysis. However, the baseline OGRS scores (a measure of how likely someone is to reoffend) have been  published and so I was able to compare a CRC’s predicted reoffending rate to the baseline OGRS rate, adjusting for differences in the likelihood of reoffending between the baseline and the October to December 2015 cohorts. The spread in differences between the baseline OGRS rate and the predicted reoffending rate for each CRC are presented in the figure below. I have anonymised each CRC because I believed highlighting relative performance in the public domain with important information missing would not be ethical. If, however, you want to know how your CRC or area is performing please contact me.

 

October to December 2015 CRC results

Source: Ministry of Justice Proven Reoffending Quarterly Statistics

Eight of the 21 CRCS were predicted to beat the baseline OGRS score. The largest difference is 5.1%, followed by two CRCs expected to beat the baseline OGRS score by  4.4%. Twelve of the CRCs were predicted to perform worse that the baseline OGRS. For five of these the difference is less 1%, but three were expected to exceed the baseline OGRS rate by more than 3%.

Next steps

The analysis presented here is based upon a description of the data. The analysis therefore does not allow for the uncertainty in the predicted reoffending rate. A more realistic analysis would present the range of outcomes that are likely to happen. The presented analysis also assumes that the data are independent. In fact a CRC’s current reoffending rate will be dependent upon the rate 3 months ago and the current rate cannot be lower than the previous measure. A statistical model can allow for these issues and I will present that approach in a subsequent blog. This does not mean the presented results are wrong. Instead, it means greater insight and use is possible as we expand the analytical approach.

Delivering Innovative Social Impact Analytics to Sodexo Justice

We are delighted to announce a new contract to deliver our ground breaking social impact analytics to Sodexo Justice, a leading provider of justice services in the UK.

The purpose of our social impact analytics is to provide definitive evidence of an organisation’s impact on society by delivering predictive analyses and impact evaluation.  Under the newly signed contract, we will measure the effectiveness of Sodexo’s six Community Rehabilitation Companies in managing the risk associated with the offenders and delivering interventions that reduce their reoffending.

By understanding “what works?” in changing lives and delivering safer communities, our social impact analytics will also be used by Sodexo Justice to measure the impact of its services.  Sodexo Justice will be paid through a payment by results mechanism that measures its success in reducing reoffending.

Our founding director, Jack Cattell said, “We very much look forward to providing our social impact analytics to Sodexo Justice Services.  Our SIAs will provide offender managers with the information they require to manage resources and deliver high quality interventions to reduce reoffending.”

Crime doesn't pay written on a blackboard

CRC Reoffending Rates: Who’s Striving, Who’s Struggling?

CRC Reoffending Rates: Who’s striving, who’s struggling? Or should we all move to the North West?

Last week the MoJ released the interim Community Rehabilitation Companies (CRCs) proven reoffending rates for cohorts that started orders or licences between October and December 2015. As it is now 12 months since the first payment by results cohort started, I thought it would be interesting and helpful to review the performance of the CRCs – the final results will be available in October 2017. If you don’t know, the CRCs are privately run probation services set up in 2014 to manage less harmful offenders and to reduce reoffending rates. As such, part of their payment from the Ministry of Justice is based upon how well they reduce reoffending compared to a 2011 baseline. If the reoffending rate increases the CRC’s contract could be terminated.

The payment mechanism is complex – see here for the important documents. The basics are that if the CRC’s reoffending rate is lower than the 2011 baseline rate, having adjusted any differences in offenders’ likelihood of reoffending, then the CRC will receive a payment. Being just 0.1% lower would not be good enough to trigger a payment – the CRC’s rate must be statistically significantly lower (I have not found in the public domain information on how significant the reduction must be – do contact me if you know of a source).

Not enough data have been released to estimate which CRC will receive a payment (the 2011 baseline rates have not been published for example) but there are enough published data to assess the relative performance of each CRC. Each CRC’s published reoffending rate cannot be directly compared because the CRCs’ offenders will present with varying likelihoods of reoffending. Fortunately the OGRS4 expected one year reoffending rates were published. With this information, I estimated what each CRC’s proven reoffending rate would be if likelihood of reoffending was exactly the same in company (the adjusted rate – I used the average OGRS4 rate across all CRCs which was 45.7%). The results are in the chart below.

Figure 1: Interim and adjusted reoffending rates in the 21 CRCS (Oct to Dec 2015 Cohort, reoffending rate to December 2016).

Table showing Interim and adjusted reoffending rates in the 21 CRCS
Source: Interim proven reoffending statistics for the Community Rehabilitation Companies and National Probation Service supporting tables January 2017. See table for bases.

There is a large 17.2% spread in interim proven reoffending rate in the MoJ data. This is reduced to a 9.5% spread in the adjusted reoffending rate. The lowest adjusted rate is in Merseyside (34.4%) and the highest is in Warwickshire & West Mercia (43.9%).  There appears to be regional clustering at the top and bottom of the chart. Three of the four CRCs with the lowest adjusted rates are in the North West – Merseyside, Cumbria and Lancashire and Cheshire & Greater Manchester – and the neighbouring areas South Yorkshire, Humberside, Lincolnshire & North Yorkshire, and Durham Tees Valley make up three of the four areas with the highest adjusted rates. This clustering could be due to police practice, the CRCs’ effective work, efficient court processes or in or an unknown factor altogether.

These results do not mean the providers in the North West can expect a payment to come their way. We do not know the baseline to which they will be compared and there is another 6 months of convictions data to be included (the proven reoffending measure includes offences within 12 months that are convicted within 18 months). Also there is likely to be an area effect that is not included in the OGRS4 measure but will be in the 2011 baseline rate. However, the differences do suggest that persons interested in how to reduce reoffending rates should visit the North West to understand if they are doing anything different there.

Table 1: Results in all 21 CRCs

Table Showing Results in all 21 CRCs

Source: Interim proven reoffending statistics for the Community Rehabilitation Companies and National Probation Service supporting tables January 2017.