Creation of Non-Governmental Primary Schools in Rural Guinea Bissau

Updated: Oct 14, 2020
Evidence Rating:
Near Top Tier


  • Program:

    The creation of non-governmental primary schools in rural Guinea Bissau, providing four years of schooling (pre-primary through third grade) in lieu of government-provided or other existing schooling in the community. Teachers were recruited and trained to teach in the program schools, assisted at the start by a local adult who spoke the most prominent language in the village, and monitored through classroom observations. They focused on teaching Portuguese language acquisition in the pre-primary year, and the national curriculum in grades 1-3. Guinea Bissau is often considered a “failed state” in which public services, including government-provided schools, are frequently low quality and unreliable.

  • Evaluation Methods:

    A well-conducted randomized controlled trial (RCT)[1] with a sample of 49 villages in rural Guinea Bissau. The villages contained 2,112 children in their pre-primary year who were tracked over the four years of the study.

  • Key Findings:

    At program completion approximately four years after random assignment, the study found large, statistically significant effects on a standardized math and reading assessment (the study’s pre-specified primary outcome measure). Specifically, treatment group students correctly answered 70% of questions compared to 11% for control group students, with large, statistically significant effects found on both the math and reading subtests, and on early skills as well as more advanced skills (e.g., math word problems, reading comprehension).

  • Other:

    The study was conducted in a single country — Guinea Bissau. As a next step in the research, a replication RCT in another country where primary education is also low quality and unreliable would be desirable to hopefully confirm these results and establish that they generalize to other settings. In addition, longer-term follow-up of this study would be desirable to see whether students’ learning gains persist once they leave the program schools at the end of third grade.

Arnold Ventures’ Evidence-Based Policy team continuously monitors and reviews the evaluation literature in international development, as we do in domestic U.S. social policy, to identify programs with credible RCT evidence of important effects on people’s lives. However, given our organization’s focus on U.S. social policy, we only provide “highlights” of our evidence reviews for most international development programs (as shown above), without the accompanying detailed PDF summaries that we provide for U.S. programs.


[1] For example, the study had successful random assignment (as evidenced by highly similar treatment and control groups), modest sample attrition, blinded test administrators, and an analysis that appropriately accounted for the fact that whole villages rather than individual children were randomly assigned. The sample attrition rates were somewhat different for treatment and control group students (13% and 26%, respectively). However, the study analysis found that the program produced large effects regardless of any reasonable assumptions about how attrition might affect the findings.

Fazzio, I., Eble, A., Lumsdaine, R.L., Boone, P., Bouy, B., Hsieh, P.T., Jayanty, C., Johnson, S., & Silva, A.F. (2020). “Large Learning Gains in Pockets of Extreme Poverty: Experimental Evidence from Guinea Bissau.” NBER Working Paper No. 27799.