Leeds University academics say the Government should forget "the sentimental rhetoric" of its advertising campaign - "No-one forgets a good teacher" - and provide some hard-nosed inducements. They interviewed 50 teachers for a study funded by the Economic and Social Research Council, and sent questionnaires to 500.
Dr Jim Donnelly, author of the report, said: "This was not the original emphasis of our research, but to our astonishment no more than two or three of the teachers interviewed suggested that they always wanted to be teachers."
One had been made redundant, another had become pregnant and felt the job would fit in with family life, and a third signed up after her boyfriend moved. A footballer turned to teaching after suffering a broken leg.
Dr Donnelly said: "Their reasons for choosing teaching were pragmatism and convenience. Sometimes people fancied staying on at university for an extra year and felt that a postgraduate certificate of education looked like a fairly safe option." But many stillturned out to be very good teachers, he added.
On recruitment, Dr Donnelly said: "We need policies to encourage people into teaching rather than relying on high-flown vocational rhetoric." He proposed that graduates who go into teaching should have their student loans paid off by the Government.