They would agree, as would I, that teachers with the highest qualifications are not automatically the "best" teachers in the classroom.

BBC: NEWS | UK | Education | What makes a good teacher?

The researchers say that once they had taken in to account other factors which can affect educational achievement and earnings and the individuals' highest qualifications, there was a link between maths and pay.

BBC: Maths skills add up to higher earnings, study finds

From January 2014, "only the highest quality qualifications" will be included in the tables, the Department for Education said.

BBC: Many vocational courses axed from league tables