Mr Marshall, a researcher at the University of Bangor, says his research shows that the percentage of modern languages graduates who are unemployed is lower than that of graduates with degrees in practical areas such as computing and engineering.
He surveyed teachers' views on what motivated their pupils in taking or dropping languages post - 16. He also spoke to students to gauge their attitudes to languages. And he compared unemployment rates among graduates in different fields.
He found that unemployment among language graduates was lower than the rate for graduate as a whole, and lower than a range of more vocational subjects.
"There's a feeling that people who are doing languages and only languages are narrowing down their job opportunities," he says. Most Year 11 and 12 students believe it's a choice of teaching or translating. And that doesn't account for anything like the majority of jobs that languages graduates go into."
In 1998, the top choices of jobs for languages graduates were in business services, manufacturing and wholesale and retail, Mr Marshall discovered.
"There are hundreds of thousands of jobs advertised simply asking for graduates, and that's the field in which languages graduates seem to do so well," he says. "I think it's got something to do with their having a better mix of generic graduate abilities than the others, or at the very least a better ability to sell themselves."