Title page 1

Contents 7

Editorial 4

Acknowledgements 6

Executive Summary 9

One in three adults has weak foundational skills 9

Adults with low foundational skills are not a homogeneous group 9

Adult learning systems fail the people who need them most 9

The profile of the low-skilled population matters for policy 10

What the evidence requires from policymakers 10

1. How many adults have low skills, and why does it matter? 11

How are foundational skills assessed? 13

How many adults have low foundational skills? 15

Are there more adults with low skills than a decade ago? 17

What are the economic and non-economic consequences of low skills? 20

References 29

Notes 30

2. Do countries face different low-skill challenges? 32

Introduction 34

How broad are foundational skill deficits? 34

How deep are foundational skill deficits? 36

Do countries face fundamentally different challenges? 46

References 49

Notes 50

3. Who are the adults with low foundational skills? 51

Introduction 52

Who has low literacy or numeracy skills? 53

A closer look at the characteristics of adults with low skills and their economic and non-economic outcomes 59

Barriers to participation in adult education and training for adults living with low skills 66

References 68

Notes 69

4. What can policy do to support adults with low foundational skills? 71

Introduction 73

What is the rationale for policy intervention? 73

How can adults with low foundational skills be reached? 74

What are the features of successful policy design? 77

What enabling conditions support learning success? 80

What roles does prevention play in addressing low foundational skills? 85

How does the nature of the challenge shape the policy response? 87

References 91

Table 1.1. Foundational skill domains assessed in the 2023 Survey of Adult Skills 13

Table 1.2. How low and medium skills are defined in this report 14

Table 1.3. One in three adults has low foundational skills 15

Table 1.4. How many adults have low skills, and why does it matter? Chapter 1 Annex tables 29

Table 2.1. Some adults with low skills reach Level 2 in some domains; few go beyond it 36

Table 2.2. Four reader profiles defined by speed and accuracy 43

Table 2.3. Four country profiles capture fundamentally different foundational skills challenges 47

Table 2.4. Do countries face different low-skill challenges? Chapter 2 Annex tables 49

Table 3.1. Who are the adults with low foundational skills? Chapter 3 Annex tables 68

Table 4.1/Table 4.2. Each country profile implies a different primary policy challenge 87

Figure 1.1. Most low-skill prevalence is driven by adults who completed the full assessment 16

Figure 1.2. The share of adults with low foundational skills has increased in many countries 18

Figure 1.3. Adults with low skills are far more likely to be inactive than those with medium skills 21

Figure 1.4. The wage penalty for low skills exceeds USD 10 per hour in some countries 22

Figure 1.5. Returns to foundational skills continue beyond medium proficiency 23

Figure 1.6. Adults with low skills report worse health and lower life satisfaction in most countries 25

Figure 1.7. Low skills are associated with lower trust and volunteering in most countries, but not always with lower political efficacy 28

Figure 2.1. Most adults with low skills are weak in both literacy and numeracy 35

Figure 2.2. The typical adult with low skills performs at Level 1 in literacy 37

Figure 2.3. Country rankings by numeracy depth differ markedly from those by literacy 38

Figure 2.4. Assignment to components 39

Figure 2.5. Reading slows before the Level 1 threshold, then speeds up as proficiency rises 40

Figure 2.6. Reading speed varies widely among slow readers 41

Figure 2.7. Most adults with low skills understand most sentences correctly 42

Figure 2.8. Reader profiles among low-skills adults differ sharply across countries 44

Figure 2.9. Restricting to native-born adults reduces cross-country variation in reader profiles 45

Figure 2.10. Breadth and depth of low foundational skills do not tell a consistent story 46

Figure 3.1. Own and parental education consistently predict low foundational skills 54

Figure 3.2. Education, occupation and social background are the top predictors of low skills 57

Figure 3.3. Few variables account for most of the predictive power of the models 58

Figure 3.4. In most countries, education is the strongest predictor of having low skills 59

Figure 3.5. The socio-demographic profiles of adults with low skills vary across countries 62

Figure 3.6. Distribution of adults with low skills, by outcomes profiles 64

Figure 3.7. Socio-demographic profiles do not determine outcomes profiles 65

Figure 3.8. Work-related reasons are the most common barriers to participation in adult learning 67

Boxes 17

Box 1.1. The doorstep interview in the 2023 Survey of Adult Skills 17

Box 1.2. Comparability between Cycle 1 and Cycle 2 of PIAAC 19

Box 1.3. Wage gradients for proficiency in literacy, numeracy and adaptive problem solving 23

Box 1.4. Measuring non-economic outcomes in the 2023 Survey of Adult Skills 24

Box 2.1. Components 39

Box 3.1. LASSO and random forests: two approaches to identify influential variables 56

Box 3.2. K-modes clustering: identifying profiles within the low-skilled population 61

Box 4.1. Programmes for Basic Skills in Switzerland 75

Box 4.2. The Unionlearn programme in the United Kingdom 76

Box 4.3. Skills for Success in Canada 78

Box 4.4. Building a professional infrastructure for the adult education workforce in England 80

Box 4.5. Financial Incentives for Unemployed Adults with Low Foundational Skills in Germany 81

Box 4.6. The Qualifica programme in Portugal 82

Box 4.7. Skills Plus in Norway 83

Box 4.8. Literacy for Life Campaign in Australia 85

Box 4.9. Integration Courses for Migrants in OECD countries 89

Box 4.10. Multiply Programme in the United Kingdom 91