For much of the twentieth century, the defining challenge for advanced economies was expanding access to education. Today, the challenge is different - and in many ways more difficult. It is what happens to the millions of adults who are left behind as the skill requirements of work, technology and daily life continue to rise.
The latest evidence from the 2023 Survey of Adult Skills delivers a stark message: nearly one in three adults across OECD economies lacks the foundational literacy or numeracy skills needed to adequately participate in modern economies and societies. Tasks that many take for granted - finding a specific piece of information in a written document, following straightforward instructions, completing a form, or carrying out simple calculations with everyday numbers and measurements - can become unsurmountable challenges for them.
These foundational skills are not specialised competencies reserved for high-skilled occupations. They are the skills needed to understand a payslip, complete an online application, follow workplace procedures, compare prices, manage household finances, or access public services. In a world that increasingly assumes a baseline level of literacy and numeracy, adults lacking these skills are not simply at a disadvantage – they are at risk of being excluded from opportunities that others routinely access.
More troubling still, the problem is not receding. Despite decades of investment in adult education and training, the share of adults with low foundational skills has grown over the past decade. At precisely the moment when economies are becoming more knowledge-intensive and technology-driven, a substantial segment of the adult population is falling further behind.
This is not a marginal issue affecting a small group on the fringes of society. It is a structural challenge that sits at the heart of economic performance, social cohesion and democratic resilience. In an era defined by digital transformation, artificial intelligence and rapid labour market change, foundational skills have become the essential infrastructure of opportunity. When large numbers of adults lack them, the consequences extend far beyond individual hardship. Productivity suffers, labour shortages become harder to address, social inequalities deepen, and democratic participation weakens.
This report examines the scale, nature and consequences of low foundational skills across OECD countries. Drawing on the 2023 Survey of Adult Skills, it moves beyond simple counts of who falls below proficiency thresholds to explore the depth and composition of skill deficits. It asks not only how many adults struggle, but how far behind they are, whether their challenges lie primarily in literacy or numeracy, and how these patterns vary across countries and population groups. By identifying distinct profiles among low-skilled adults, the report seeks to provide policymakers with a more precise map of the challenge - and a clearer guide to effective action.
The evidence leaves little doubt about the stakes. Adults with low foundational skills face substantial disadvantages in employment, earnings, health and civic engagement. These are not temporary setbacks that disappear with age; they persist throughout the life course, accumulating into significant economic and social costs. The analysis suggests that helping adults reach at least medium levels of proficiency could generate meaningful gains across all these dimensions.
Yet here lies the central paradox of adult learning policy. The adults who stand to gain the most from improving their skills are often the least likely to participate in education and training. Barriers of confidence, awareness, time, language and access mean that many remain beyond the reach of conventional provision. Left unaddressed, this dynamic creates a self-reinforcing cycle in which skills gaps translate into fewer opportunities to acquire new skills, widening inequalities over time.
The implication is clear: a one-size-fits-all approach will not succeed. Adults with low foundational skills are not a homogeneous population, and policy responses must reflect that reality. Effective strategies need to be differentiated according to the depth of skills deficits, the domains in which they occur, and the role that migration and language background may play. They must also be proactive, bringing learning opportunities into workplaces, communities and everyday settings rather than relying on individuals to seek them out. Above all, they must be sustained. For adults facing significant foundational challenges, lasting progress rarely comes from short courses or isolated interventions. Building foundational skills is not a quick fix; it is a long-term investment in people, productivity and social inclusion.
Andreas Schleicher
Director for Education and Skills and Special Advisor on Education Policy to the Secretary-General
Organisation for Economic Co-operation and Development (OECD)