The findings call into question the Government's policy of rewarding colleges based on the number of students who complete courses.
In a paper to be presented at the British Educational Research Association conference next month, Phil Hodkinson of Leeds University and Martin Bloomer of Exeter University call for a radical rethink of procedures so that students who drop out can be given the help they need.
Over the course of three years, they conducted at least five interviews with each of 50 students who went on to FE courses after GCSEs. Between five and seven dropped out, depending on the definition used.
Their research found that for several students, the decision to drop out has "as much, if not more, to do with life outside college as with the teaching within it". In almost every case, the young person reacted to pressures by backing off and escaping into another life.
The researchers say that in all cases, what the colleges offered was influential, but most students also exercised a crucial influence on their own fate - by failing to complete coursework, for example.
Students' "dispositions to learning" and their experiences are constantly changing, say the researchers.
"Dispositions to learning can change as a consequence of educational experiences ... but (they) can also be influenced by events outside.
Educational and non-educational influences are significant, and it is how they interrelate that matters."
Hodkinson and Bloomer state that current approaches to the problem might be making matters worse and different approaches could be introduced.
However, this would require "accepting that dropping out is likely to remain a significant and sometimes legitimate part of FE experience" no matter what a college or its staff do. Students, though, often find it very difficult to get professional help and most are likely to be pressured to stay on their course.
They believe more help should be given to students in danger of dropping out: "What many needed was supportive counselling, including careers guidance, when they started to drop behind with their studies, when problems occurred, or when circumstances andor dispositions significantly changed."
The cost of counselling or mentoring potential drop-outs might be high but, the researchers point out, "the cost of not providing such support is arguably even higher".
Sue Dutton, deputy chief executive of the Association of Colleges, said there were a multitude of reasons for student drop-outs. However, financial problems were paramount.
'Dropping out of FE:the nature and complexity of educational failure', by Phil Hodkinson, school of continuing education, Leeds University and Martin Bloomer, school of education, Exeter University.