UNESCO has historically relied on official enrollment numbers from administrative data sources and UN population projections to estimate the number of children not in school.

However, in recent years household surveys have been offering additional, even if at times not fully consistent, information that had not been mainstreamed. Using multiple sources was advocated by the United Nations in 2015 in its call for a data revolution. UNESCO has accordingly developed a new methodology to combine all sources to improve out-of-school estimates.

Administrative data showed rapid reductions in out-of-school in the first decade of the millennium but slow progress in the second decade. The new methodology now being used corroborates this general trend but adds important nuances.

Results are available on the VIEW website, enabling users to take a closer look at the data and the sources for each country, at each age group. A factsheet summarizes the main findings.

The out-of-school population fell from 401 to 244 million in two decades.

In 2000, an estimated 401 million children, adolescents and youth of school age were not in school, with just under one in five children of primary school age excluded worldwide.

Since then, the percentage of primary-aged children out of school has fallen by more than half. Similar progress has been made at the secondary level. Today, 244 million are still excluded.

While this reduction marks substantial improvements in school access, progress has been uneven. The out-of-school population declined by 123 million between 2000 and 2010 but only by 34 million between 2010 and 2021.

The share of out-of-school primary-aged children from sub-Saharan Africa increased from 31% in 2000 to 55% in 2021.

The new data being released today can be broken down by region, income group and country. And the new way of measuring also helps fill gaps for some countries.

This is the case for Pakistan and Nigeria, which each have about 20 million children and youth out of school, Ethiopia (10.5 million) and the Democratic Republic of Congo (6 million). These are important red flags for advocacy groups focusing on leaving no child behind and country planners.

Out-of-school rates have stagnated even more among secondary school age adolescents and youth. They decreased by only 2.3 and 6.1 percentage points among lower and upper secondary school youth respectively between 2010 and 2021, well below the progress achieved the decade before.

Fewer girls than boys have been out-of-school since 2007 but various gaps persist

The number of girls out of school fell below that of boys in 2007. Today’s new data shows that there are 119 million girls out of school versus 126 million boys.

Globally, there is almost no gender gap in out-of-school rates for each of the three age groups but significant differences remain by region, especially among those of upper secondary school age: while in sub-Saharan Africa, for instance, the female out-of-school rate is 4.2 percentage points higher than the male rate, it is 3.1 percentage points lower in Eastern and South-eastern Asia.

Out-of-school rate gender gap (female–male), by age group and SDG region, 2021

More time will be needed to assess the impact of COVID-19 on school access

This new analysis has confirmed that the 2010s were a lost decade in terms of progress towards even the modest goal of universal primary education that was meant to be achieved by 2015. It is likely that countries, whose progress had been held back in the 1980s and 1990s, took all the steps in the 2000s that would allow them to make up for lost time but have since lost steam.

The potential contribution of external support, which had helped many countries get back on track at the time, weakened in recent years and stagnation set in.

The new analysis offers some new nuances that inform all our work.

• First, the total out-of-school population is estimated to be 13 million or 5% lower than previous estimates based exclusively on administrative data.
• Second, a different picture emerges with respect to the numbers out of school between the three age groups: the primary out-of-school rate has been declining faster than previously thought, even if the rate of decline has slowed down.
• Third, the new information gives a fuller account of the contribution of some countries, such as Nigeria and Ethiopia as mentioned above, for which administrative data have been incomplete or lacking, to the global out-of-school population.

On the other hand, while the model improves our understanding of the past, it is not as sensitive to the recent impact of COVID-19, which disrupted not only school attendance but also education management information systems all over the world.

The model incorporates administrative data from the 2021 school year, but this is not enough to demonstrate whether COVID-19 has brought about a long-term trend shift. Preliminary evidence suggests that while primary and lower secondary education enrollment might not have been affected, there might be some impact on upper secondary enrollment.

The forthcoming UIS data release on September 13 will offer the latest insights into year-on-year changes in enrollment by country and education level.

While recognizing the limits of statistical approaches in the face of events such as the recent pandemic that introduce considerable uncertainty, it is also important to recognize the substantive contribution of this new approach.

The approach follows one already used to calculate completion rates, which also feature on the VIEW website. Similar methodologies have been used to estimate flagship health indicators for over 15 years, which also rely on administrative and survey data sources.

Other indicators such as those on school infrastructure or teacher education would also benefit from a robust methodology like this that would enable the use of administrative and household or school survey data sources.

The use of multiple data sources can offer greater confidence in regional and global trends to help better monitor SDG 4.