Impact of out-of-field teaching on school results in Brazilian high schools: An analysis with panel data from the School Census

In 2016, 21\% of Brazilian high school teachers were only teaching out-of-field assignments. To what extent does this affect school results? Is it necessary for a teacher to have formal education strictly compatible with the subject taught, or is it that good teachers are capable of teaching any subject? Based on a panel built with the School Census of Basic Education and using a fixed school effects model, we estimate the impact of out-of-field teaching in four schools results seldom used in the literature: dropout rate, age-grade distortion, approval rate and retention. The main result points to a positive and significant relation with dropout rate and age-series distortion. Systematic issues such as dropout and age-grade distortion seem to be accentuated with out-of-field teaching. Results are robust to gradual addition of controls and persistent in the subsamples of schools run by states, located in urban areas and in the Northeast region. These results suggest that one of the mechanisms for understanding the lack of interest of young people in school can be found in the role of teachers.