Fact check: What are the links between school exclusions and knife crime?

School exclusions are in the news again this week after a group of police chiefs and London’s mayor demanded action from the government to tackle knife crime.

In a letter to Theresa May, Sadiq Khan and seven police and crime commissioners linked a “broken” school exclusion system in England to a rise in knife crime.

While there’s plenty of research showing a correlation between exclusion and involvement in crime, there’s little evidence proving a causation

In their letter, Khan and the commissioners said there was “growing evidence to show that our vulnerable children are more likely to be excluded or off-rolled from school” and noted that “excluded children are at much greater risk of becoming either perpetrators or victims of serious youth violence”.

Both of these statements are technically true. Pupils eligible for free school meals, those with special educational needs and children from certain ethic groups such as Gypsy, Roma and Traveller are disproportionately more likely to be excluded from school.

Excluded pupils are also twice as likely to carry a knife as their peers.

But while there’s plenty of research showing a correlation between exclusion and involvement in crime, there’s little evidence proving a causation – essentially that excluding a pupil is a primary cause of their involvement in gang violence or knife crime.

A study released by the Ministry of Justice last year found that although young people caught carrying a knife were more likely to fail at school or be persistently absent, only a “very small proportion” committed their offence shortly after being excluded.

Sadiq Khan has called for a change to school exclusions

The department found that although it was “not possible to identify from this analysis whether there is an association between exclusions and knife possession offending”, the low volumes of offences following exclusions “mean any such association could not be a significant driver of youth knife possession offending overall”.

Ofsted joined the debate this week, insisting it had seen “no convincing evidence that exclusions, in and of themselves, lead to knife crime or gang violence.

“It was, however, likely that exclusions are caused by the same underlying factors as violent crime and therefore affect many of the same young people.”

A recent report from Anne Longfield, the children’s commissioner for England, highlighted “extensive evidence linking school exclusions with gang involvement”, and warned that some alternative provision for excluded pupils has become “gang grooming grounds”.

But Longfield’s report also points to wider problems beyond the school gates.

Anne Longfield

For example, gang members are 95 per cent more likely to have social, emotional and mental health issues than others who were assessed by children’s services, and they are much less likely to get extra funding if they have a special educational need or disability.

In a letter to The Times this week, Tom Bennett, the government behaviour adviser, warned that it was a “mistake” to attribute knife crime to exclusions, and warned of confusing correlation with causation, adding that “most knife crime occurs either simultaneously with exclusion or more than a year later.

“These are symptoms of the same causal forces, such as poverty and gang culture, which are complex and hard to solve easily,” he said.

School leaders also seem to be concerned about the recent rhetoric from leading figures around these issues.

Many have pointed out that schools are unfairly being blamed for wider societal problems such as poverty and the effects of austerity, of which poor behaviour and subsequent exclusion from school may be a symptom, rather than a cause.