Over the last 2 years we have been working with Social Housing providers across the UK to explore how the application of behavioural insights could increase revenue and reduce costs.

In line with our commitment to evidence-based practice, we encourage the use of randomised controlled trials (RCTs) wherever possible. This case study showcases an RCT that triggered a 24% increase in customer engagement, just by simplifying the layout of a letter and reducing cognitive friction.

For the organisation behind this trial, customer contact is a central pillar of the income collection strategy. The fact that a customer has made contact demonstrates a basic level of responsibility and commitment to resolving the debt. Furthermore, customer contact allows income collection officers to take a more tailored approach to resolving the case successfully.

This trial applied changes to existing debt recovery communications based on three well documented behavioural principles: simplification, fear appeals and emotional content.

Trial Design

There is a wide range of psychological barriers preventing customers from engaging with organisations to which they are indebted[i]. For the social housing provider involved in this study, increased customer engagement was one of the key elements in creating a more tailored approach to debt recovery.

As with most income collection functions, there was a recognition that there are customers who can’t pay and those who won’t pay. A reliable method of differentiating between these two scenarios will enable more tailored and effective intervention.

This trial was used to elicit the most basic demonstration of responsibility and commitment to resolve the debt (contact), as the foundation for more reliable ways of differentiating the can’t pays from the won’t pays.


Our own research has shown that arrears communications and letters tend to be verbose, vague and poorly designed. Using basic information design principles to inform the use of colour, icons and content hierarchies, we redesigned existing letters to aid instant comprehension and enable a clear, specific behavioural response.

Negative Vs Positive Emotional Content

In addition to testing the simplification techniques referred to above, we also incorporated two contrasting messages, focusing on Positive and Negative consequences of inaction.

The Negative intervention was designed around a ‘Fear Appeal’ and the threat of losing one’s home; the Positive intervention was designed around a positive depiction of the future and the prospect of a ‘debt-free life’.


  • Contact us now, or risk losing your home.
  • Contact us now and break free from your debt.
  • When you signed your tenancy agreement you made a legal commitment to pay your rent on time.


  • We know that being in debt can be very stressful for you and your family.
  • There is still time for us to stop this action [seeking possession of home], but we can only do this if you get in touch.
  • We want to help you get debt-free and stress-free, but we can only do this if you get in touch.

The sample comprised all tenants who were due to receive the second letter in the organisation’s arrears escalation process.

Each participant was randomly allocated to 1 of 3 trial arms, with two intervention groups receiving either the Positive or Negative condition, and a control receiving the existing stage 2 arrears letter.


An average of 51% of the sample contacted the organisation over the course of the trial.

However, there were large and significant differences in favour of the intervention groups.

  • 24% more tenants in the Negative group made contact than in the control group
  • 16% more from the Positive group made contact than the control group.

Testing showed the results to be highly statistically significant (p=<0.001) with both interventions being significantly different to the control.

If you’d like further details on this case study or would discuss how the application of behavioural insights and evidence-based innovation could impact your organisation, leave a comment on this article or PM me directly.


[i] Collard, Sharon (2013). Working Together: Understanding Motivations and Barriers to Engagement in the Consumer Debt Marketplace. Arrow Global, Bristol.

[ii] n=547