A report into Norfolk County Council's placement of vulnerable children into boarding schools over the last 10 years found that out of 52 young people that took part, 37 (71.2 per cent) saw a reduction in their level of risk by the end of the placement.
Of 17 children who were in care to begin with - nine (52.9 per cent) were no longer looked-after by the end of the placement.
Meanwhile, although two of the 16 children on protection plans at the start of the placement went on to be taken into care by the end of the placement (12.5 per cent) and a further two (12.5 per cent) remained at the same level of risk, one child (6.3 per cent) decreased to being considered a "child in need", and 11 (68.8 per cent) were dropped down to universal services.
Norfolk County Council's scheme originated in 2008, coinciding with a Labour government pilot initiative.
It is now part of the Boarding School Partnerships - a DfE collaboration with the Boarding Schools Association, Royal National Children's SpringBoard Foundation, Buttle UK, and the Reedham Children's Trust - which launched in July 2017.
The study, supervised by University College London's Institute of Education, also reported improved educational attainment for the young people. Of the 33 whose educational outcome was available, 64 per cent achieved at least one GCSE or equivalent qualification.
The report attributed the improved educational and risk outcomes to the stability and pastoral care that boarding schools offer. It also credited Norfolk's process for matching children with schools and monitoring placements.
Dr Wendy Thomson, managing director of Norfolk County Council, said: "Our research shows that with the right placement, boarding schools can enable children and families to remain together. Most importantly, children and young people feel valued and supported, giving them a far better chance of achieving their potential in life."
Boarding schools may also save councils money, the study found. The research noted that in Norfolk the annual cost of a boarding school placement was £11,000 to £35,000 a year compared with an annual £56,000 bill for supporting a looked-after child.
Schools minister Lord Agnew said the findings demonstrate the role boarding schools can play in helping vulnerable young people: "I urge local authorities to consider these findings and the positive impact boarding school placements can have."
Richard Watts, chair of the Local Government Association's children and young people board, said: "When it comes to housing vulnerable children, councils will always try to provide the most appropriate placement for an individual child's needs.
"For most children, this will be in a family home such as that provided by foster carers or extended family, where they can get the love and support that they need to flourish, but social workers will always consider a range of options, whether that's foster care, a children's home or another form of provision."