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It's elementary: students benefit from pre-primary education.
The OECD's PISA 2009 results show that in practically all OECD countries 15-year-old students who had attended some pre-primary school outperformed students who had not. In fact, the difference between students who had attended for more than one year and those who had not attended at all averaged 54 score points in the PISA reading assessment - or more than one year of formal schooling (39 score points). While most students who had attended pre-primary education had come from advantaged backgrounds, the performance gap remains even when comparing students from similar backgrounds. After accounting for socio-economic background, students who had attended pre-primary school scored an average of 33 points higher than those who had not.
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PISA 2009 finds that the relationship between attending pre-primary school and better student performance at age 15 is strongest in school systems that offer pre-primary education to a larger proportion of the student population, that do so over a longer period of time, that have smaller pupil-to-teacher ratios in pre-primary school and that invest more per child at the pre-primary level of education.
Do the benefits of attending pre-primary school add up to better overall performance among those
school systems in which more students have access to pre-primary education? Although PISA results do not show any relationship between the average performance of OECD countries and the proportion of students in those countries who had attended pre-primary school, when all countries and economies that participated in PISA 2009 are considered, a positive relationship between the proportion of these students and a country's performance emerges - even after taking the country's national income into account. For example, school systems that have a 10 percentage-point advantage in the proportion of students who had attended pre-primary school score an average of 12 points higher in the PISA reading assessment.
A growing body of research recognises that early childhood education programmes improve children's well-being, help to create a foundation for lifelong learning, make learning outcomes more equitable, reduce poverty and improve social mobility from generation to generation. Results from PISA suggest that participation in pre-primary education is particularly strongly associated with reading performance at age 15 in those countries where policies have sought to improve the quality of pre-primary education. Building on this evidence, the OECD is developing an online policy toolbox to help policy makers formulate and implement policies to improve the quality of early childhood education and care.