The Peterborough Social Impact Bond (SIB) conspiracy

If you think Social Impact Bonds are the biggest thing to hit public policy EVER, then you were probably horrified at the cancellation of the final cohort of the flagship Peterborough SIB. How is it possible? What does it mean?

Since the news was broken in April this year (2014), I’ve had questions from as far afield as Japan and Israel trying to discover the UK Government’s TRUE agenda. More recently, at the SOCAP Conference in San Francisco in August, it was raised again. Eileen Neely from Living Cities, which has provided $1.5 million in loan financing for the Massachusetts Social Impact Bond was discussing “shut down risk: what happens if one of the parties decide they don’t want to play.”

She said, “In the Peterborough deal in the UK, the government decided that they weren’t going to play any more… so there’s some who say ‘Oh it’s because it wasn’t going well’ and others are saying ‘It was cos it was going too well’ so whichever it is, they decided that they weren’t going to do it, that they weren’t going to go into the next cohort, so what does that mean to the investors?” Eileen made it quite clear “I haven’t talked to any of the participants there, I’m just outside, reading the articles and the blogs …”

I thought it was about time we summarised the evidence for those who continue to ask these questions. Continue reading

What do the Peterborough SIB interim results tell us?

Update: actual results are now out.

First cohort results from the Peterborough SIB were released August 7 2014. The Social Finance UK press release on the results has lots of great information, with a quote below.

“Results for the first group (cohort) of 1000 prisoners on the Peterborough Social Bond (SIB) were announced today, demonstrating an 8.4% reduction in reconviction events relative to the comparable national baseline. The project is on course to receive outcome payments in 2016. Based on the trend in performance demonstrated in the first cohort, investors can look forward to a positive return, including the return of capital, on the funds they have invested.”

Outdated information below:

Peterborough Interim ResultsOn the 13th of June, the Ministry of Justice released interim results from the Peterborough Pilot SIB. The results were seen as very encouraging, although Social Finance stressed that the results “do not measure  reoffending behaviour over as long a period as the Social Impact Bond will be judged and are not compiled on precisely the same basis as will be used by the Independent Assessor during the course of 2014 to determine whether a payment is due.”

What the results do tell us

The results tell us that the reoffending events have improved in the Peterborough cohort as the national average has worsened. We can be fairly confident that the reduction in reoffending is due to the Peterborough SIB, or more specifically the One Service. This in itself is quite an achievement for Government policy.

These results are also an excellent demonstration of the need to have a contemporary comparison, in this case the Police National Computer control group, rather than a historical baseline. If the historical re-conviction rates at Peterborough had been used as the only comparison, it would appear that a 6% reduction had been produced. Using the national comparison group shows that the programme also counters an increasing trend in re-convictions to produce a relative reduction of 23%. The inability of historical baselines to represent the fluctuating environment affecting reoffending is further illustrated when we look at results leading up to the 2010 launch of the One Service. The graph below shows that reoffending by both Peterborough inmates and prisoners across the nation was increasing until SIB services began in 2010, but then reversed in comparison to the national rates.

Peterborough Interim Results 2

What the results don’t tell us

The results do not tease out for us which aspects of the One Service might be more or less responsible for success. So, the results do not tell us if the reduction in reoffending is due to the:

  • use of volunteer mentors
  • voluntary, rather than mandatory, participation
  • long-term nature of the SIB funding
  • flexibility of funding
  • ability to innovate programme delivery to optimise outcomes
  • focus on a single outcome
  • extraordinary skills of the people involved in managing and delivering services
  • continuous evaluation and improvement of the One Service
  • discipline of reporting to external investors
  • alignment of financial and social returns.

The April 2014 evaluation commissioned by the Ministry of Justice from Rand Europe sheds some light on the perceived benefits of the SIB model, including the way the flexibility of funding allows for the service to improve in response to performance management data.

Update April 2014

See 24 April results and press release from the Ministry of Justice stating “Before the pilot, for every 100 prisoners released from Peterborough there were 159 reconviction events annually. Under the scheme this figure has fallen to 141 — a fall of 11 per cent. Nationally that figure has risen by 10 per cent over the same period.”

Toby Eccles blog analyses how well the Peterborough SIB achieved its objectives to:

  • Enable innovation
  • Enable flexibility and focus on outcomes
  • Bring rigour to prevention
  • Better alignment
  • Investment in social change.

And a good analysis of the Peterborough journey and what was learnt is given by the Social Spider here. I have a slightly broader view of SIBs in the context of policy reform, but I like the discussion.


Ministry of Justice, Statistical Notice: Interim re-conviction figures for the Peterborough and Doncaster Payment by Results pilots12 June 2013.

Social Finance, Interim Re-Conviction Figures for Peterborough Social Impact Bond Pilot, press release 13 June 2013.

Ministry of Justice, Mentoring Scheme Reduces Reoffending, press release 13 June 2013.

Vibeka Mair, Peterborough social impact bond has slashed reoffending rates says MoJ, Civil Society Finance, 13 June 2013.

Alan Travis, Pilot schemes to cut reoffending show mixed results, The Guardian, 13 June 2013.

BBC, Prison payment-by-results schemes see reoffending cut, 13 June 2013.

Nicholls, A. & Tomkinson,E. Case Study – The Peterborough Pilot Social Impact Bond – Oct 2013, Oct 2013.