This remarkable impact, calculated as part of the investigation for the national review of FE, means that, in effect, colleges are turning every Pounds 1 into an asset worth pound;3.20 a year.
"Colleges transform people's lives and give opportunity in many other ways," according to the interim report from a working group on the difference colleges make. "This represents an excellent return on investment."
The number of enrolments in FE also shows healthy activity - up from 234,000 in 1994-95 to 394,000 in 2004-05 on vocational programmes, an increase of around 70 per cent. Almost three-quarters of enrolments resulted in a pass or a completed course.
By coincidence, a former education minister has delivered the same message in a rare political acknowledgment of the contribution of FE. In a fulsome tribute to the sector in his regular Scotland on Sunday column, Brian Wilson stated that "in terms of bangs for the buck, FE delivers magnificently for society", particularly in deprived areas.
The report from the working group notes that "colleges are pivotal to the delivery of lifelong learning in Scotland" and that "no other sector can match the range of courses that colleges deliver".
It endorses Mr Wilson's wider social point that "there are important links between the acquisition of skills and wider social outcomes, such as improving health, reducing crime and enhancing social cohesion".
While colleges provide a bridge for school-leavers to later life, the study found that 58 per cent of college enrolments of working age adults are the direct result of links to industry.
The economic impact analysis was based on 14,536 individual students who increased their qualification level between entering and leaving college (although the report is at pains to say that this does not mean there is no value attached to gaining an additional qualification at the same or a lower level).
This was then subject to complex adjustments, including the salary values of each qualification, the costs of educating students and retirement assumptions.
The resulting estimate of a pound;1.3 billion benefit to the nation is a cautious one, the report states. "A large amount of the college activity that we identified was excluded from our model because it did not lead to a certified or specifically identified qualification," it comments.
"There is likely to be a benefit to doing these courses, but we cannot vouch for its scale. In the absence of robust data, we have taken the conscious decision to be cautious in our assumptions around the benefit calculations."
The working group which produced the report acknowledged that colleges do not just make a positive impact on the economy but on learners and society as a whole.
There has been no reliable data in the past on where students go or what they do after leaving college. The Scottish Funding Council has now begun a longitudinal survey of both FE and HE. The first results, published in June last year, showed that three in five regard their studies as a good investment and the majority who were in a job believed it was appropriate to their level of skills and qualifications.
The students who took part will be surveyed again in 2007 and 2009.
In his column, Mr Wilson singled out John Wheatley College in Glasgow's east end for the key contribution it makes to skills training and community regeneration. "In many ways, the east end of Glasgow is the litmus test for both Labour government and devolution," he commented.
The FE review is also looking at accountability and governance, the staff and student environments and colleges' long-term strategic future. The final report on the review as a whole will be published in 2007 with the intention that its recommendations should influence the executive's next round of spending decisions.
What students say
* "I want a job."
* "(If there) was no college), I'd have been forced into a dead-end job."
* "College is the reason why I get up in the morning."
* "Without college, boredom would have resulted in me returning to drugs."
* "(Undertaking a college course) would be something to fall back on if I failed the university course."