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Seeds and saplings
Preliminary findings from an evaluation of business support programmes
16 July 2026
Several months ago, we began an analysis of the long-term impacts of business support programmes on participating companies. We evaluated:
- GrowthAccelerator (> 20,000 businesses) – a competitive programme run by the Department for Business and Trade (DBT), with companies admitted if identified as having high-growth potential by expert assessors. Successful businesses completed the GrowthMapper diagnostic tool and were given access to leadership and management training and 1:1 coaching (participants).
- Growth Impact Pilot (546 businesses) – an RCT embedded within GrowthAccelerator, with companies randomly assigned to receive either leadership and management training (treatment 1) or training plus 1:1 coaching (treatment 2).
- Innovation Vouchers Programme (1,463 businesses) – an RCT run by Innovate UK, with companies randomly assigned to either receive an innovation voucher (treatment) or no voucher (control).
The premise of these programmes was to attract businesses with the potential for growth or innovation, and to contribute to their success.
Our analysis was motivated by 2 overarching questions:
- Did the programmes spot high-potential businesses?
- Did the programmes make winners by supporting these businesses?
Disclaimer: This work was undertaken in the Office for National Statistics’ (ONS’s) Secure Research Service using data from ONS and other owners and does not imply the endorsement of the ONS or other data owners.
Let all flowers bloom
Before we present the results, take a moment to imagine a participating company. What type of business is it? How large is it? Where is it located?
Having trouble? Indeed there is no one answer to these questions, and therefore no “typical” business that accessed support. Not every business was eligible: companies in GrowthAccelerator (and the Growth Impact Pilot) had to meet turnover and employment criteria, and applicants to the Innovation Vouchers Programme needed an innovative project with a knowledge provider. But apart from these basic requirements, any business was able to participate.
And so they did. The SMEs within the support programmes were hugely diverse:
- Sectors – from agriculture to retail, manufacturing to services
- Size – from single individuals to hundreds of employees
- Regions – all English (GrowthAccelerator / Growth Impact Pilot) and UK regions (Innovation Vouchers Programme) represented
In line with Nesta’s influential research, this huge diversity of businesses was an intentional feature of the programmes, which aimed to support all sorts of high-potential endeavours. However, this diversity had a profound effect on our analysis, and our findings must be understood in this context.
The garden of forking paths

From huge diversity of participants, to a huge range of outcomes: after their involvement in the support programmes, businesses went on to widely diverging fates, from shutting down entirely to becoming superstar high-growth companies. This variation was much higher than expected from the interim data used for the original power calculations, highlighting how outcomes can diverge strongly over longer timescales (our primary outcomes were measured over the 4-5 years after programme participation).
Why does this matter? First, it highlights the importance of measuring outcomes over longer timescales to capture the true potential, and pitfalls, of interventions. Second, there are powerful methodological implications. The more variable and unpredictable are outcomes, the lower the statistical power and higher the risk that we cannot identify a true difference between participants and comparison SMEs, or between experimental conditions. And when considering diversity itself – for instance, when comparing outcomes in different regions – this problem is even more pronounced.
Another challenge comes from the datasets we used. Our analysis used the ONS Longitudinal Business Database (LBD), which is a valuable resource containing turnover and employment data for millions of businesses, but it does not capture other, more nuanced information. Businesses vary in ways that we cannot observe in this data – like looking at only the stem of a plant visible above the ground, unable to see the roots.
Answering key questions
Overall, we found strong evidence that the support programmes spotted high-potential businesses, but no evidence that the programmes made them into winners.
Did the programmes spot high-potential businesses?
Yes! Our results are consistent with the idea that the business support programmes attracted and identified high-potential companies.
In both the Growth Impact Pilot and the Innovation Vouchers Programme, a propensity score weighting analysis showed that participating companies generally outperformed other SMEs:
- Growth Impact Pilot participants generated £453,000 more turnover and 11.6 more jobs in the four years following participation, and £18,000 more turnover per employee at the end of this period.
- Innovation Vouchers Programme participants generated £478,000 more turnover and 10.6 more jobs in the five years following participation, but £15,600 less turnover per employee at the end of this period.
In GrowthAccelerator, a comparison between participants and a matched comparison group (identified via propensity score weighting) produced even stronger results:
- GrowthAccelerator participants generated £1.1 million more turnover and 15.2 more jobs over the four years after participation, but not significantly more turnover per employee, when compared to matched “twin” companies.
These results strongly suggest that the programmes attracted businesses that were high-quality and more likely to succeed than other SMEs.
We also found a strong relationship between the expert assessor scores and business potential:
- The higher the expert assessor score, the more likely a GrowthAccelerator applicant business was to achieve high-growth status in the four years after participation – a key outcome the programmes were trying to target.
This suggests that GrowthAccelerator not only attracted, but correctly identified those businesses with the most potential.

Did the programmes make winners by supporting these businesses?
We don’t know for sure. A lack of statistical power and concerns about matching quality make drawing clear conclusions difficult. We found:
- The treatment group in the Growth Impact Pilot generated less turnover and no new jobs over the four years following participation, when compared to the control group. These differences were not statistically significant due to low statistical power – we could only have been confident of outsized impacts.
- The treatment group in the Innovation Vouchers Programme generated £114,000 more turnover and 5.9 more jobs over the five years following participation, when compared to the control group. However, these differences were not statistically significant, again due to low statistical power.
- We also found that businesses in the treatment group received £55,500 more funding from Innovate UK, a significantly higher amount than the control group.
On the surface, the findings we presented above suggest huge impacts for the GrowthAccelerator programme. But as discussed, the challenge of finding comparison twins undermines the credibility of these headline figures. Additional difference-in-difference analyses comparing sub-groups of participants also present a more mixed picture:
- Takers experienced no additional impacts when compared to non-takers.
- Early participants experienced no additional impacts on turnover or productivity, but the latest cohort demonstrated significantly weaker natural job growth before entering the program than the earliest cohort did during the same timeframe.
Overall, we cannot confidently say that participating companies in GrowthAccelerator experienced better performance by taking part in the programme nor can we say that they did not..
Taken together, the null results from the RCTs and the mixed results from GrowthAccelerator should be interpreted as no evidence of impact on our primary outcomes of interest, rather than evidence of no impact.

However, for IVP our research collaborators have already shown how vouchers had beneficial impacts on earlier outcomes (innovation collaborations, product and service development, internal processes, and intellectual property protection) and we find new evidence of additional innovation funding.
Given the statistical challenges but also the rapid policy cycles (GrowthAccelerator was closed before any of these findings became available), we believe that future experiments should focus on testing early impacts, critical for success, even when planned as full impact evaluations.
Reaping and sowing
Our experience shows that evaluation, particularly over long timescales, is challenging. But there is much we can and will do in the coming weeks, months and years:
- Peek under the ground – improve matching quality and credibility by leveraging more sophisticated statistical techniques
- Dig deep – campaign to enrich business datasets through additional data linking
- Capture early growth – encourage new support programmes to collect interim data to capture signals prior to high variation
- Follow the trail – pursue a better understanding of how the “ladder of support” influences business outcomes, and explore the potential of data generated by diagnostic tools (e.g. GrowthMapper)
What happens next?
Although we are analysing old programmes, the questions we have asked are as timely and relevant as ever. Across the UK government, there is a renewed interest in how best to target, and support, high-potential businesses. Our analysis suggests that business support programmes are able to find and attract high-potential businesses, but it is much less clear whether they are able to accelerate growth.
Our work is ongoing:
- With input from DBT and Innovate UK, we will finalise and publish our analyses.
- We will share learnings about methodological challenges, and campaign for better data access and linkages.
- Supported by The Productivity Institute, we will undertake further research to investigate the role and value of diagnostic tools like GrowthMapper.
- We will bring members of the IGL policy and research networks together through a shared learning agenda about high-growth businesses.