Hard core truants cost the economy £800 million each year, according to a new study.
The child, hampered by poor qualifications, can expect lower earnings but the price paid by society includes lower tax receipts, higher crime plus increased pressure on health services and benefits.
And one third of this could easily be saved, according to figures from the New Philanthropy Capital (NPC) organisation which advises charitable donors.
Each of the UK's 200,000 persistent truants costs £44,468 over their lifetime, the NPC study Misspent Youth states. For all persistent truants, this amounts to £8.8 billion or £800 million each year. Each of the 10,000 exclusions a year costs £63,851.
The NPC calculations - based on data from charity accounts, evaluations of projects, academic research and Government publications - are the first attempt to estimate the lifetime costs of truancy and exclusions.
The NPC hope it could lead to a more responsible allocation of resources. But the report concludes: "We have taken a deliberately cautious approach to this data and, as a result, the estimates represent minimum figures." Overall the aggregate costs "represent a staggering waste of economic potential" particularly as cheap and cost-effective solutions exist, it states.
Trying to tackle the problems that lead to truancy and exclusion can reap big rewards, it suggests. Two schemes - School-Home Support and The Learning Challenge - show ways in which some of the costs can be avoided, the study states. Each charity succeeds in tackling the underlying problems, and reducing truancy or preventing exclusions, in up to a third of cases.
School-Home Support provides social support in primary and secondary schools in London and Yorkshire and the Humber. Working with a broad range of children aged from six years old, it deals with school problems that originate in the family such as domestic violence and substance abuse, tackling behavioural problems and increasing self-esteem.
The Learning Challenge, which operates in the North East, runs intensive classes for truants to address their behavioural problems and helps increase school attendance. Each £1 spent by The Learning Challenge produces £11.60 in savings, the NPC calculates.
The study said: "An aggregate saving of £2.7 billion would be made if all preventable persistent truancy was tackled, the equivalent of £250 million per annum. This would pay for an extra teacher in every secondary school in the UK."
