The role of preschool in reducing inequality

Preschool improves child outcomes, especially for disadvantaged children

Columbia University, USA, and IZA, Germany

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Elevator pitch

Children from disadvantaged families have lower levels of school readiness when they enter school than do children from more advantaged families. Many countries have tried to reduce this inequality through publicly provided preschool. Evidence on the potential of these programs to reduce inequality in child development is now quite strong. Long-term studies of large publicly funded programs in Europe and Latin America, and newer studies on state and local prekindergarten programs implemented more recently in the US, find that the programs do improve outcomes for young children, particularly for those from disadvantaged families.

The share of children aged 3–5 in
                        preschool varies across OECD countries, 2010

Key findings


Small model preschool programs improve child outcomes, especially for children from disadvantaged families.

Large public programs delivered at scale improve outcomes for children from disadvantaged families.

Preschool programs raise children’s school readiness.

The benefits of high-quality preschool programs persist into adolescence or young adulthood and, in most cases, are larger for more disadvantaged children.

High-quality preschool pays for itself, both by raising students’ overall achievement and by reducing inequality of achievement.


High-quality preschool programs are expensive.

Highly educated and well-trained preschool staff and reasonable class sizes and teacher–student ratios are required for high-quality preschool.

Results of studies of the effects of preschool programs may not be generalizable across countries.

As children enter school more ready to learn, schools need to be positioned to support and build on those gains.

Evidence is stronger with regard to positive short-term effects; but benefits are not always maintained in the long term.

Author's main message

Universal preschool programs implemented in many countries in the 1970s and 1980s led to improvements in academic achievement and other positive outcomes, particularly for children in disadvantaged families. A new generation of preschool programs being implemented in some US cities and states have also had positive outcomes. Good-quality preschool programs more than pay for themselves by boosting achievement and reducing inequality of achievement. That is good news, especially for countries with persistent and high levels of inequality—and a good reason to expand preschool programs in countries where enrollment is far from universal.

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