Going to university in England is still a good investment for young people, says an annual international report, which rejected claims there were too many graduates.
The study from the OECD economics think tank says despite facing among the highest tuition fees in the world, the increased earning power of graduates would still "greatly exceed the cost".
"Educated people throughout history have always argued there are too many other educated people," said the OECD's education director Andreas Schleicher.
But he argued that universities needed to face much more scrutiny over the quality of courses and qualifications.
Mr Schleicher said that at school level, the UK education systems were leading the world in measuring how pupils progressed - but at university level, there was much less information about how students were learning.
He rejected arguments that too many people were going to university - but said if universities expanded further there needed to be more clarity about standards and what they were offering students in terms of future employment.
The report showed a narrowing gap in the higher earnings of graduates across the UK.
In 2013, graduates had average earnings that were 54% higher than non-graduates, which had reduced to a 42% advantage in 2017.
Below these averages, there were significant differences - such as higher earnings for those who studied maths and sciences and lower earnings for graduates of arts and humanities.
Despite this likely outcome in earnings, the OECD report said universities in the UK had increased places for arts and humanities at a greater rate than in-demand subjects such as engineering.
Demand for graduates
Mr Schleicher said the debate about too many people staying in education had always been there - and there was no real evidence of any reduction in demand for graduates and highly skilled people.
"If we had this discussion a hundred years ago, there would have been people saying there were too many people going to high school," he said, at the launch of the report in London.
There were no signs of modern economies needing fewer well-qualified people, he said.
The report showed the strong international growth in higher education - with 44% of people aged 25 to 34 across the OECD now having degrees, compared with 35% a decade ago.
But that "doesn't mean everyone has to go to university", said the OECD education director.
High quality vocational education was also needed - and Mr Schleicher said there was a "disturbing picture" in which those who already had the worst skills were the least likely to be able to get extra training.
Head teachers' best paid
The annual report also highlighted the ways in which teachers' pay in England was unlike other countries.
It showed that relative to graduate earnings, head teachers in England were better paid than in any other country in the developed world.
But classroom teachers, by the same measure, had below-average pay.
The levels of starting salaries for teachers in England were also below average by these international comparisons.
In the recent round of spending announcements, the Department for Education said that it would increase starting pay for teachers in England to £30,000.