BBC Wales education correspondent
Much earlier intervention is needed to tackle truancy and poor behaviour in schools in Wales, according to experts.
The National Behaviour and Attendance Review, after a two-year study, says issues need to be addressed in primary schools to "nip these problems in the bud."
It also wants intensive training for child welfare professionals and teachers to deal with bad behaviour.
The Welsh Assembly Government is to develop an action plan in response.
The steering group was made up of teachers, academics, and representatives of children's charities, police and social agencies, chaired by Professor Ken Reid, of Swansea Metropolitan University.
The government here in Wales is clearly worried about truancy - why else would they ask one of Britain's leading experts to spend two years compiling this report?
And they have cause to be. Truancy is without doubt the biggest problem for schools in Wales.
Studies consistently show children who miss significant amounts of school are less likely to find employment and a stable home life.
They're much more likely to get involved in crime or spend much of their lives on benefits. The legacy of missed school is long and damaging.
According to Welsh Assembly Government figures around 16,500 are away from lessons every day. Some are so called "authorised absentees" - away on holiday, or ill - but many are missing because they're truants.
Spotting the potential truants early is crucial, according to Prof Reid.
There is a clear link between low literacy and behavioural and attendance problems
A large number of professionals feel under-trained in handling attendance and behavioural problems
There are too many 'unofficial exclusions' from certain schools and a wide variation in the way the rules are applied
The number of pupils out of school is not properly monitored
There is a wide disparity in provision for out-of-school pupils in different council areas
Children should be listened too more closely on these issues
Greater inter-agency cooperation needed
Changing trends including the rise in behavioural problems among girls
There is a rise pupils displaying problems well before Key Stage 3
All secondary schools needed a named professional to lead on these issues
An assembly government action plan needs immediate and long term priorities
Source: National Behaviour and Attendance Review (NBAR) report
At the moment he says help for disaffected students is geared towards those aged 14 plus.
"That's too late," he told me. "You have to get in early if you want to make a difference."
Reading and writing is key. Unless they have those skills by the time they reach 11, Prof Reid says the future is bleak.
"Pupils who do not have the ability to read and write by the time they leave primary school fall further behind with their schoolwork," he said.
"They are the pupils who become truants, they misbehave, they're likely to get involved with bullying, they're likely to be the pupils who are excluded and when they leave school they are likely to be the pupils who have major problems in their adult lives."
The evidence is, says Prof Reid, that around 20% of Welsh children are not achieving the sort of results they should by 11. That means thousands of children could be at risk.
He said he was taking into account the fact that many more pupils from Wales come from a disadvantaged backgrounds and that truancy issues date from about 1870.
"Even allowing for that, the fact remains that an awful lot of pupils underachieve in primary school and go on to underachieve even more when they get to the secondary stage and that is leading to further problems," said Prof Reid.
So what does the report say about dealing with pupils who have been temporarily or permanently excluded?
Prof Reid says legislation should be introduced by the assembly government compelling schools and education authorities to continue their education within days of their exclusion, rather than allowing them to roam the streets.
Increasingly councils are using the courts to deal with the parents of truanting children.
Local councils are increasingly using their powers and in recent years a number of parents - mainly mothers - have found themselves being imprisoned.
Prof Reid says jailing parents is "headline grabbing" but he is doubtful that prison has any long term effect on parents of persistent truants.
"It should only be used as a last resort," he said.
These recommendations - including early intervention, training, increased emphasis on reading and writing - represent a seismic shift in policy.
If they're adopted they will need significant funding and at a time of national belt tightening, is the money in the education kitty?
Education Minister Jane Hutt said it was a "comprehensive body of work on a very important aspect of our education system".
She said the views of pupils themselves had provided a "valuable insight" into the key issues surrounding behaviour and attendance.
Ms Hutt said a working group would be set up to develop an action plan by early next year in response to the recommendations.