There are more A-level pupils studying media studies than economics
Only three economics teachers were trained on teacher training courses in the whole of England last year, shows a study of students entering teaching.
The report's author, Professor Alan Smithers, warns that economics risks "dying out" as a school subject.
There are now more pupils taking A-levels in media studies, expressive arts and PE than economics.
This makes it harder for universities to recruit economics students, says Professor Smithers.
The figures on the training of students to become economics teachers emerged from a wider annual study of recruitment into teacher training - for the year 2006-2007.
Professor Smithers, from the University of Buckingham's Centre for Education and Employment Research, says the figures for economics teachers on postgraduate teacher training courses were so low that he had the statistics from the teacher training agency re-checked.
They show that there were only three economics teachers trained - out of an intake into teacher training of more than 38,000 students.
This group contained almost 2,000 trainee teachers for both English and maths, 3,000 for science and even 29 for classics.
Professor Smithers says that he understands there were a couple of other trainee economics teachers entering by other employment-based routes - perhaps making an annual total of around five.
The lack of specialist teachers, he suggests, is an indication of the endangered status of the subject - which has suffered a substantial loss of pupils at a time when there has been an overall increase in A-level student numbers.
"Economics might seem like an important subject for politicians and the media - and they might even make it seem sexy, but it does not have an established place in schools," says Professor Smithers.
The figures for economics A-level students have been in a prolonged downturn - down by more than a quarter between 1996 and 2006 to about 17,000 - with the subject overtaken by a range of other subjects that have become much more popular.
There are three times as many pupils taking psychology A-level as economics and almost twice as many taking A-level media studies. Sport and physical exercise and the expressive arts are now bigger subjects at A-level than economics.
Professor Smithers says it remains uncertain why so few students are entering teacher training for economics - or why the subject is in decline in schools.
Among the suggestions, he offers, are that economics is a difficult subject, requiring a strong grasp of mathematics, which limits the numbers of those able to enter the subject.
Economics is also not part of the national curriculum, which could have squeezed the subject in some schools, he suggests.
There might also be a shift away from the demanding academic discipline of economics towards more general business qualifications.
The decline of a subject at A-level can create a self-perpetuating downward spiral - a pattern that has already been seen in modern languages, with French A-level numbers almost halving in a decade.
Fewer A-level pupils means a smaller pool of potential recruits for university economics courses - and the economics graduates that do emerge from universities then have many options other than entering teacher training.
And with the subject declining in schools, there is a disincentive for trainee teachers to enter a subject area with a shrinking number of jobs.