Around £2.6 trillion more could be generated for the UK economy if the nation ensured that all of its pupils had basic skills in areas like reading and maths, according to an education expert.
Around one in five UK 15-year-olds struggle with the most basic tasks in the OECD's Programme for International Student Assessment (Pisa), according to Andreas Schleicher, the thinktank's director for education and skills.
Pisa covers subjects including reading, maths and science.
In a speech due to be delivered at the Education World Forum in London on Monday, Mr Schleicher will say: "It's tempting to think that at least the high-income OECD countries would have all the means to eliminate extreme underperformance in education.
"But that isn't the case. For example, one in five 15-year-olds in the United Kingdom do not successfully complete even the most basic Level 1 PISA tasks.
"If the United Kingdom were to ensure that all students had at least basic skills, the economic gains could reach $3.6 trillion (£2.6 trillion) in additional income for the economy over the working life of these students, or 1.4 times the size of the current economy.
"To put it differently, the economic gains that would accrue solely from eliminating extreme underperformance in high-income OECD countries would more than pay for the primary and secondary education of all students.
"Such improvements in educational performance are entirely realistic.
"For example, Poland was able to reduce the share of underperforming students in Pisa by one-third, from 22 per cent to 14 per cent, within less than a decade. Shanghai in China reduced the share of underperforming students between 2009 and 2012 alone from 4.9 per cent to 3.8 per cent."
Mr Schleicher will also suggest that in general, students across the world may benefit from more teamwork.
"In today's schools, students typically learn individually and at the end of the school year, we certify their individual achievements," he will tell the conference.
"But the more interdependent the world becomes, the more we need great collaborators and orchestrators. Innovation is now rarely the product of individuals working in isolation but an outcome of how we mobilise, share and integrate knowledge.
"Also the wellbeing of societies depends increasingly on their capacity to take collective action.
"Every day we are seeing how the mere interaction of billions of individual humans, taking their own autonomous decisions, can combine to create systemic risks with potentially catastrophic consequences.
"Schools, therefore, need to become better in helping students to learn to develop an identity that is aware of the pluralism of modern living, and to join people from different backgrounds in life, work and citizenship.
"That means teaching and rewarding collaboration as well as individual academic achievement, enabling students to think for themselves and to act for and with others.
"Collaborative skills have become a catchword in many education systems, but the reality is that students sit most of the time behind individual desks and there is limited time for collaborative learning."