A study of 80,000 people across Britain carried out by Peter Robinson at the London School of Economics found that workers with Highers are on earnings levels comparable to five or more O-levels or GCSEs. Mr Robinson points out that the assumption that Highers are equivalent to A levels is not substantiated.
Mr Tuck said most Scots with Highers went to take other qualifications such as degrees. "Highers are very well regarded in Scotland and I would be surprised if there were any questions against their currency," he said.
Under the education and training targets for Scotland, three Highers are equivalent to two A levels to recognise the breadth and depth of the English courses.
Higher Still reforms would stress "equal worth" between academic and vocational routes when they were under the one assessment system, Mr Tuck said.
Academic path pays better, page 16