MST Standard
UK and international research indicates that MST is a cost-effective intervention as evidence suggests it reduces the cost of placing children out of home and also costs associated with offending and anti-social behaviour.
Data from the Washington State Institute for Public Policy indicates that the savings from implementing MST are between $12 and $28 for every $1 of spend (Aos et al 2001). Data also indicates that the outcomes of MST are sustained over time, with the longest follow up study now following people up to 22 years post intervention.
Audit data from existing MST sites in England supports these findings from the USA, suggesting that MST provides cost savings in terms of out of home placement, offending costs, police time and educational provision.
An Economic Evaluation of Multisystemic Therapy for Young People at Risk for Continuing Criminal Activity in the UK was carried out by Maria Cary & Sarah Byford at King’s College London, based on data from a randomised controlled trial conducted at the Brandon Centre in North London.
Focusing on costs and savings in terms mainly of offending costs, they found that, in comparison to usual care:
  • MST reduced criminal activity and saved £2290 per young person over two years of follow-up;
  • MST reduced the need for youth justice services and saved £1217 per young person over two years;
  • MST cost £2285 per young person, but saved a total of £3,507, resulting in overall (net) savings of £1222 per young person over two years. 
These findings were consistent over time, and showed the same pattern of results when 3-year data were analysed.
This study presented some methodological limitations as data were limited to youth justice related costs and the analysis was limited to cost savings, ignoring the impact of MST on outcomes for young people.
The Department of Health, in conjunction with the Department for Education, has funded a pragmatic multi-centre randomised controlled trial (the START trial) to evaluate the effectiveness and cost-effectiveness of MST in a UK context. This trial involves nine pilot sites and 684 participants were successfully recruited. 
MST for Child Abuse & Neglect (MST-CAN)
Please see below for the UK and international studies have investigated the cost effectiveness of MST-CAN:
Cambridgeshire study
During the course of the research pilot, Cambridgeshire County Council completed a cost benefit study through York Consulting (2014). This small study included 10 families that had completed MST-CAN. Results showed that the fiscal return on investment ranged from zero to 13.6. The average overall was positive at 6.2. This indicates a savings of £6.20 pounds for every £1 pound of support invested.
Leeds study
A programme evaluation of MST-CAN in England (Watmuff and Ross 2016) included a preliminary cost-benefit analysis, the findings of which suggested that every £1.00 spent on MST-CAN returned £1.59 in benefits associated with range of outcomes (e.g. reduced incidences of taking children into care, reduced alcohol and drug dependency, improved mental health) as compared to the assumed costs of usual services.
Swiss study
Researchers (Pérez et al. 2018) in Switzerland used cost-comparison analysis to examine the actual costs of MST-CAN (based on program budgets) versus the hypothetical costs of alternative interventions (based on social workers’ reports of the contingency plan for each youth referred to MST-CAN, in the event there had not been an opening in the program). Results indicated that the costs of MST-CAN were 16–50% lower than the costs of the contingency plans, the majority of which were out-of-home placement.
U.S.A based studies
A rigorous economic analysis of the findings obtained in Swenson et al. (2010) examined the monetary benefits of MST-CAN relative to its costs across individual (e.g., future mental health treatment), taxpayer (e.g., social services, out of home placements), and societal (e.g., reduced crime) domains (Dopp, Schaeffer, Swenson, & Powell, 2018). Every dollar spent on MST-CAN recovered $3.31 in savings to participants, taxpayers, and society at large. Thus, the initial upfront expenses of MST-CAN services more than pay for themselves in a relatively short period of time.
For information about the cost effectiveness of MST-CAN, please read this article: Economic Impact of Multisystemic Therapy for Child Abuse and Neglect