One in five British students leave school without acquiring basic skills, according to a new report commissioned by the Organisation for Economic Co-operation and Development (OECD).
The report, titled 'Universal Basic Skills: What countries stand to gain', was produced by economists Eric Hanushek and Ludger Woessmann.
It includes the biggest ever global school rankings, which rank 76 countries according to how well their students perform. The analysis is based on test scores in maths and science, and is an expansion on the OECD's Pisa test scores.
Asian countries dominate the top of the rankings, with Singapore heading the table, followed by Hong Kong in second place and South Korea in third.
The United Kingdom ranks 20th, and the United States comes in at number 28.
MAPPED: Global school rankings
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Of the European countries, Finland scored the highest ranking, in sixth place.
Ghana scored lowest overall, putting it at the bottom of the rankings.
The report also ranked countries based on the share of students who do not acquire basic skills - what the report's authors define as a score of below 420 in the maths and science assessments on which their ranking data is based.
In the UK, 20 per cent of students failed to meet the level of basic skills.
Writing on the OECD's 'educationtoday' blog, OECD education director Andreas Schleicher stated that the report shows that "the quality of schooling in a country is a powerful predictor of the wealth of that countries will produce in the long run."
However he cautions that, as the report shows, even high-income countries still have some way to go to meet the goal of universal basic skills.
"Even high-income OECD countries would gain significantly from bringing all students up to basic skills by 2030.
"For this group of countries, average future GDP would be 3.5 per cent higher than it would be otherwise."