New study demonstrates “large positive effects” of single-sex schools

17 May 2016

Associate Professor C. Kirabo Jackson, a labour economist at Northwestern University in the United States, has studied twenty low-performing, co-educational government secondary schools converted into single-sex schools under a Ministry of Education program commenced in Trinidad and Tobago in 2010. Jackson found that, even after accounting for student selection, there were “large positive effects” of 0.14 standard deviations for both boys and girls attending the single-sex pilot schools in national exams for academic subjects taken three years after entry. In addition, students in the single-sex cohorts were “more likely to earn the secondary school leaving credential” and the all-boy cohorts had lower engagement in crime.

In addition to analysing student outcomes, Jackson also administered student surveys at single-sex pilot schools and a set of comparison co-educational schools in 2013, 2014 and 2015. These surveys suggested that there are “positive direct peer effects in all-girls settings through less peer distraction, less peer disruption, and more peer learning”. There was also “evidence of efficiency gains to the more homogeneous single-sex classrooms because teachers spend more time one-on-one time with students in single-sex classrooms despite no change in cohort size”.

Jackson concluded that “the results indicate sizable [sic] benefits to single-sex schooling for the student population under study”. He also noted that:

The test score effect of 0.16 standard deviations is about as large as the effect of going from a teacher at the 6th percentile of teacher quality to one at the 50th percentile of teacher quality. To achieve equivalent results through increases in school spending, reductions in class size, tutoring, or other interventions would require a nontrivial financial outlay. The results of this study illustrate the potential cost-effectiveness of leveraging peer effects (both direct and indirect) to improve student outcomes (both educational and otherwise).

Given that the benefits obtained from converting nearby pairs of co-educational schools into single-sex schools incurs “zero financial cost”, Jackson argues that “the evidence demonstrates that single-sex education can be an effective low-cost way to improve student outcomes”.

Note: Staff members of Alliance schools can access a research abstract of Kirabo Jackson’s article via the Research Library:


Jackson, C. K. (2016, May). The effect of single-sex education on academic outcomes and crime: Fresh evidence from low-performing schools in Trinidad and Tobago. National Bureau of Economic Research, Working Paper 22222. Retrieved from: