How many children in the world are getting a proper education?

For many children schools do not live up to their promise: in many schools children learn very little.

This is a problem in rich countries. By the end of primary school about 9% of children in high-income countries cannot read with comprehension.

But it tends to be a much larger problem in poorer countries. This is what the chart below shows. The education researcher Joāo Pedro Azevedo and his colleagues estimate that in the very poorest countries of the world 90% of children are not able to read with comprehension when they reach the end of primary school.

Many of these children do eventually learn how to read, but the problem of poor learning persists: these children are already behind by the end of primary school and the issue compounds over the years so that many of them leave school with a poor education.

The same data also shows that it doesn’t have to be this way: in the best-off countries the share of children that fail to learn how to read with comprehension at that age is less than 2%.

Children need to learn to read so that they can read to learn. When we fail to provide this to the next generation, they have fewer opportunities to lead rich and interesting lives that a good education offers. It crucially also leaves them in a poorer position to solve the problems of tomorrow.

What explains this large problem and how we can do better?

One obvious reason why many children don’t learn is that they are not in school or that they drop out; this is the case for 8% of the world’s children and I discussed this problem before here.

But the problem is bigger than that. Many children who don’t learn are in school.

What the research shows is that getting children into the classroom is only half the battle. Many education systems are failing to ensure that the children who arrive at school every morning actually learn.

For this we need data. But the international statistics on education have not yet caught up with this reality. They still very much focus on school attendance. Even the most prominent index measure of development – the UN’s Human Development Index – only captures attendance. It doesn’t capture whether or not children learn.

To be clear, we should also keep tracking access to schools. Schools are not just about learning – it is where children socialize, they provide safety and often food, and they make it possible for parents to work.

We need the statistics to capture both aspects: the quantity of education – how many years a child spends at school –, but also the quality of education.

One way of assessing which schools live up to their promise is to study test scores. I think that an excessive emphasis on tests in school education is misplaced. But I also believe that the vast differences in test scores that this data reveals tell us something important about the world. It offers us the opportunity to understand why some schools are failing and how we can do better.

In recent years several research teams have done the hard work of piecing together test results to produce global data on learning outcomes.

The one that I rely on was produced by researchers Dev Patel and Justin Sandefur.

The bar chart at the beginning showed the large differences in learning outcomes between rich and poor countries. The data by Patel and Sandefur also reveals the differences within countries. Their data also complements the literacy scores above with the other basic educational skill: numeracy.

In the large visualisation below I show all of their data on test scores in mathematics. But to see clearly what this data tells us let’s go through it step by step – first for one country, then for several, until we arrive at the global picture.

The sloping line in the small chart below shows the distribution of test scores in Brazil. It plots the students’ mathematics scores on the vertical axis against their family’s incomes on the horizontal axis.

It shows the large inequality in incomes within Brazil and it shows that the learning outcomes of Brazilian children map onto this economic inequality. The average students from rich households achieve much better scores than the average poor students.

The fact that educational outcomes correlate with the household’s income doesn’t mean that income is the only variable that matters. This is because income itself is correlated with other aspects that matter, for example the parents’ education.

It also doesn’t mean that children from poor families cannot possibly achieve a very good education. The data shows the averages along the income distribution and makes clear that poor children face much steeper odds.

Let’s add more countries to the chart.

At the center of this next plot we see again the data for Brazil, but now we can compare it with the results in six other countries.

This data shows that the differences between countries are often much larger than the differences within countries:

The majority of students in Morocco do worse than the poorest students in Brazil.The richest students in Brazil do much worse than even the poorest students in the Netherlands, Finland or South Korea.

Another insight from this chart is that some of the most successful countries – including Finland – avoid educational inequalities along the income distribution almost entirely. The steepness of the line indicates how unequal the learning outcomes in a particular country are: a steep line shows a high inequality between the poorest and richest kids in terms of learning outcomes, while a less steep line – like the line for Finland – indicates that kids from all family backgrounds do similarly well.

Finally let’s also add the data for the other 58 countries for which data is available.

For most countries the lines slope upwards: students from richer families do better in maths. Patel and Sandefur document that these within-country differences in learning outcomes are particularly large in those countries with the largest economic inequalities. Brazil is one of them.

Because test scores are such an abstract metric it is hard to grasp how very large the disparities between countries are – it’s hard for anyone to relate to a test score of 380 (the score of the richest children in Cote d’Ivoire) or a score of 545 (the score of the poorest children in the UK).

One way to make such a 165-point difference understandable is to compare it with the inequality within countries. The difference in test scores between the richest and poorest students in the US is 53 points. This tells us that the differences between countries are several times larger than the differences within countries, even a highly unequal country like the US.

This is one of the main insights from this data, the differences between countries are enormous.

There is a second key insight from this research that is worth highlighting: the average income level of the country is more important for a student’s learning than the income of the particular family within that country.

Look, for example, at the test results of the poorest students in Korea or Finland to see this striking result. The poorest Korean or Finnish students are poorer than the rich students in Brazil, but their math scores are much higher.

Or compare the scores of students whose families have an annual income of $5,000. You find a range from as low as 350 points in poorer countries all the way up to 600 points.

Let’s think about the implication of this.

In some of the world’s richest countries, like Finland, the education system is a great equalizer – it gives every child a chance, no matter what their family background is.

But in most places – and even more so in a global perspective – these educational differences are actually perpetuating the high levels of inequality. Children from richer backgrounds tend to learn much more and grow up to become more skilled and productive and make themselves and their countries richer in turn.

If we want to stop inequality perpetuating itself through education, we have to raise the quality of education for hundreds of millions of children. The most successful countries show that it is possible.

Now that we have an idea of the problem let’s see what can be done to provide better education to the world’s children,

The fact that every morning millions of children go to schools in which they learn very little is a massive challenge. I can’t blame you if you feel disheartened when you consider how we can overcome this.

But I do think it is very much possible to make progress. Let me explain why.

As always in this series on ‘The world’s largest problems in brief’, I won’t pretend that I can lay out an exact plan for how we should solve it. Particularly for education, this very much depends on the local situation. But I do want to explain why I am optimistic that change is possible.

Today a large share of the world’s children gets a poor education. But until recently almost every child had a terrible education.

We know that change is possible because it has already happened. If we look at the places where children now get a good education, nearly everyone was illiterate until recently.

Even basic skills – such as reading and writing – were only attainable for a small elite. This chart brings together estimates of basic literacy from around the world to show how this has changed.

And the world isn’t just making progress in learning basic skills. The fact that many children learn very little is often referred to as the ‘learning crisis’. But I think this is a misnomer. The word ‘crisis’ suggests that we are in an extraordinary period, worse than before. But this isn’t the case. Learning was worse in the past. In the majority of countries children are learning more now than some years ago, the world is making progress.

The change that we are seeing makes clear that there are ways forward.

It’s not only schools that matter for how much children learn. Many children struggle to learn because they suffer from poor nutrition, poverty and poor health.

What we’ve seen above, that those children in richer countries and those from richer families do much better in school, is also due to the differences in living conditions more broadly.

It is also the case that the educational progress that countries achieved was made possible by their much broader development. In the big chart above Singapore is at the very top of the international comparison. A century ago, every third child in Singapore died and the country had a GDP per capita of just $3,000. Without its large improvements in child health and growth the country could have not achieved this.

Better health, less poverty, and a more nutritious diet can often do more for a child’s education than the best teacher. This is why progress against poverty, against poor child health, and against malnutrition are key to improving the education of the next generation. The fact that the world is making progress against these problems is a big reason why I am optimistic about the future of education.

Looking at the evidence so far might have convinced you that improvements have been possible, but you may raise the skeptical question of whether this implies that further improvements can be achieved. What needs to happen to achieve a good education in those places where children learn so very little today?

There are studies that set out to answer this question.

One of the countries with the poorest education today is Guinea-Bissau. A study in the rural parts of the small Western-African country found that most children do not learn how to read and write. From their parents they can’t learn it, less than 3% of mothers were able to pass a simple literacy test. This study concluded that the quality of teaching was poor because “teachers are isolated, underequipped, receive salaries after long delays, and have little training.”

A recent study by Ila Fazzio and her colleagues set itself the goal to see what can be done when these constraints are lifted.

The researchers went to the most difficult places within the country – those regions with the lowest learning levels – and worked with the people there to set up simple primary schools.

The study’s schools trained teachers, provided them with scripted lessons, monitored children and teachers regularly, involved the village communities, and provided adequate resources to support all operations. To see whether these well-resourced schools made a difference they set up a randomized controlled trial: they compared how much the children learned in the study’s schools with children in the control group who went to schools that carried on with their teaching as they did before.

After 4 years they compared whether children learned more in the study’s schools.

In the control group the results were very poor: after 4 years only 0.09% of children were able to read. Among those children that attended the study’s school learning was much better: 64% of them had learned how to read.

The chart below shows the overall test scores, which also take into account the kids’ numerical skills. Overall test scores increased hugely – by 59 percentage points.

Other recent studies also show that it is possible to achieve very large improvements in those places where young children are otherwise illiterate and innumerate.

Even in the most challenging places – extreme poverty, very low education of parents, almost no infrastructure (no internet, no electricity, no roads) – it is possible to teach primary school children to read fluently and do basic math very well.

If it is possible to run schools in which children learn very successfully, what is the catch?

It is expensive. The cost of these schools amounts to $425 per student per year. This is about 70% of the average income (GDP per capita) in Guinea-Bissau and therefore far beyond what the country can possibly afford to spend on primary schools.

This highlights one reason why a country’s prosperity is so important for its education. What a rich country spends annually per primary school student is about 10 times as much as the average income in a poor country.

Countries need to become much richer to build schools that are as well-resourced as those in this study. Big change is possible, but it requires large increases in prosperity.

Education in those places where children learn very well is expensive. High-income countries spend more than 150-times as much on the education of each child than poor countries.

In the long run, countries will hopefully have achieved the growth they need to afford better schools, but is there anything they can do right now?

To answer this question, researchers have made a big effort in recent years to identify the most cost-effective ways to improve schools.

Instead of trying to change the entire school system, as in the study above, this research tries to find out what exactly it is that means that children learn little in a particular place, and to change those things that have the biggest possible impact for the smallest cost.

Since the problems which hold children back differ from place to place there are no universal solutions. What works in one context, might not work in another.

The research on cost-effectiveness in education shows that the very best interventions can be extremely cost-effective. The most cost-effective programs deliver the equivalent of three additional years of high-quality schooling – that is, three-years of schooling at the quality comparable to the highest-performing education systems in the world – for just $100 per child.

What are the changes that can achieve so much with so little? The recent review by Noam Angrist and colleagues highlights three in particular.

Perhaps somewhat paradoxically one reason why children in some countries learn very little is that the school curricula are too ambitious. Instead of being aligned to the students’ learning levels, most of the content goes over the students’ heads.

The suggested solution is simple: match the teaching to the learning level of the students. The kids do a test and the teaching they receive then depends on how much they already know.

In places where overly ambitious curricula are a problem this change can be extremely cost-effective – no additional inputs are needed, it is just a change in how teaching is done. These ‘teaching at the right level’-approaches are the changes that were found to result in the aforementioned three additional years of high-quality schooling for just $100.

Another problem in many places is that teachers are left to fend for themselves. They are isolated, have little training, and on top of the teaching they have to write their own daily lesson plans.

In such situations it has been shown to be very cost-effective to introduce structured pedagogy programmes in which teachers receive support and are provided with structured lesson plans.

There are also encouraging studies that show that the work of teachers can be complemented by technology-aided instruction programs.

A third cost-effective approach is to simply inform people about how very high the returns from a better education are.

Some parents and students are not aware of the enormous pay-offs of having a good education. Learning this can increase the demand for education and improve children’s learning for very little cost.

In the previous section we have seen that it is costly to bring the entire education system to fruition. In this section the takeaway is that there are some possibilities to achieve a lot with very little – there are some very low-hanging fruits.

he first insight from this research is that schooling is not the same as learning. The new data on global learning outcomes makes clear just how big of a problem this is.

The second insight is that it doesn’t have to be like this – we can change this. All children can learn.

We have a huge opportunity. The world has made big strides in getting children into schools. These children are no longer isolated; teachers are in contact with them. At the same time, researchers have identified low-cost ways to improve their learning outcomes. Taken together this gives us the possibility to turn schooling into learning.

The evidence also made clear that poor schooling is not only a problem in poor countries. Some of the most striking data discussed above showed how very unequal learning outcomes in most countries are – while some other countries show that it doesn’t have to be that way.

Much is at stake here: Humanity solves problems by understanding the world and implementing ideas for how to do better. Whether tomorrow’s generation continues to make progress against disease, poverty, poor nutrition, and environmental problems will depend on their understanding. Those of us who dedicate our lives to teaching therefore have the responsibility – and opportunity – to enable the next generation to develop these new ideas and grow up to lead a fulfilling life.