But, undaunted, Merthyr's newly created education authority has launched an ambitious drive to improve the town's results - so that half of all its pupils reach five A-C grades at GCSE by the turn of the century.
"For many years the attitude here was: 'What's the point of getting good results? It won't get me a job.'' says Robert Butcher, deputy head of Cyfarthfa High School. "But that seems to be changing. People are realising that GCSEs are important in the race to gain employment,"
In fact employment prospects today seem less bleak than for some time. After two decades in which Merthyr lost a vast number of jobs both in manufacturing and in coal-mining, investment is returning once more. St Merryn, a Cornish group that supplies meat to supermarkets, has announced that it is building a processing plant in the north of the town and will be looking for more than 600 new recruits. Halla, a Korean company, is setting up in the area and has plans to produce forklift trucks that will create more than 300 jobs. US Can and Candy have also announced investment in the town.
The unemployment rate in Merthyr is currently 9.1 per cent, far higher than the Welsh average of 7.4 per cent but lower than for 10 years. "It finally looks as though Merthyr might have turned the corner," says Ray Pearce, head of economic development at Merthyr council.
But the change in the town's economic fortunes is not the only reason that attitudes to qualifications have been changing. Just under a year ago,as part of the current local government reorganisation, Mid Glamorgan council was split into four and the tiny Merthyr Education Authority was formed, catering for just five comprehensive secondary schools. And the authority has pulled out all the stops to ensure that it reaches its target of 50 per cent of pupils getting five or more A-C grades at GCSE by the turn of the century.
A measure of its ambition is that three years ago the proportion getting five or more A-C grades was only 26 per cent. In 1996 it reached 36 per cent, still well below the 42 per cent average for Wales.
The town's headteachers believe that the small size of the authority has the advantage of allowing them to work closely together. The authority has created an Education Forum where they meet every six weeks to discuss ways of improving results.
"We know each other well, and we get on well - which helps," says John Williams, headteacher at Penydre High School, which two years ago had just 13 per cent A-C grades at GCSE. "As headteachers, we each realised that our own school had to improve its results. So it's not as if the challenge was imposed on us by the authority. We feel as though the authority has backed us. It is a small authority and in it there is a real sense that something needs to be done and that it can be done. "
Alan Pritchard, headteacher of Cyfarthfa school, agrees: "Large authorities do have economies of scale but smaller ones like ours are better for co-operation and sharing ideas. Merthyr Tydfil authority has come in with the right attitude and has forged us into a tight-knit group that wants to achieve the same ends."
Literacy is a particular problem. The borough's inspectors have discovered significant shortfalls, says Dewi Jones, Merthyr's new education director, and the Forum is planning a family literacy programme. It has set each school a target for improving reading and writing ages. The idea is to show parents how they can help their children. Parents will be urged to read to them at home and increase their vocabulary. The schools believe that if literacy levels in the area increase this will directly improve results.
The authority has also set targets for reducing absenteeism and for improving A-level results by 2000. As part of the drive for better GCSE performance, it is also supporting the schools' plans for homework clubs, revision weekends and one-week study courses in the holidays.
The heads and the authority believe that the key to reaching the targets is to build a partnership among staff, parents and pupils. Mr Jones says: "Over the next year the forum is going to discuss how to make inroads into showing parents that they are the primary and co-educators of their children. We want them to be involved far more closely."