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The "Quality of Quantity": Achievement Gains from Adding a Year to Brazilian Primary Schooling

Martins, M. L., & Carnoy, M
Year of Publication: 

“The additional year intervention in Brazil is particularly interesting for the quality versus quantity debate because students there score relatively low on international tests such as the OECD’s Program in International Student Assessment (PISA). This implies that the value added of an additional year of schooling is small, favoring the argument that investments in improved quality of each year of schooling would produce bigger achievement gains than investments in additional years.”

However, as Martins and Carnoy show, the achievement gains from Brazil's 9 year basic education reform, with its additional year of primary schooling, turn out to be very large.

This study is an impact evaluation of the policy that added an extra year in Brazilian
compulsory education. We use a difference-in-difference-in differences (DDD) strategy
to identify the effect of a one-year increase in instructional time on students’ academic
achievement by the end of the primary school level. The findings are that (1) the
additional year of schooling increases mathematics and Portuguese language achievement
in Brazilian primary schools by 0.22 - 0.26 standard deviations, controlling for student
individual and family covariates and state fixed effects; and (2) schools with students
from the highest average socioeconomic background and with the highest average test
scores made larger gains from the extra year of education than schools with students from
lower and middle socioeconomic backgrounds and lower and middle levels of test scores.
We conclude that this policy has had positive effects on school achievement in Brazil, but
that the policy may increase the gap between the highest SES students and the rest and
between already higher achieving students and the rest. Our results also suggest that an
additional year of schooling has an effect on achievement which is as large or larger than
interventions attempting to raise learning in any given year of schooling.


Martins, M. L., & Carnoy, M. The “Quality of Quantity”: Achievement Gains from Adding a Year to Brazilian Primary Schooling.