Researchers: Mauricio Romero, Justin Sandefur, Wayne Aaron Sandholtz
Sample: 3,499 students in 185 schools
The results presented here are an early analysis of the PSL program’s first-year data and represent our best effort given the limited timeframe in which policy decisions are being made. An academic advisory committee of experienced researchers has provided feedback, but these results are preliminary and have not yet been extensively peer-reviewed.
After one year, public schools managed by private operators raised student learning by 60 percent compared to standard public schools. But costs were high, performance varied across operators, and contracts authorized the largest operator to push excess pupils and under-performing teachers into other government schools.
 The World Bank. “School enrollment, primary (% net),” World Development Indicators, accessed August 28, http://data.worldbank.org/indicator/SE.PRM.NENR?locations=LR.
Liberia Institute of Statistics and Geo-Information Services. Liberia demographic and health survey 2013. Liberia Institute of Statistics and Geo-Information Services.
 Formerly “The Liberian Youth Network.”
 Because they were not subject to the same contracts, neither Bridge International Academies nor Stella Maris received the extra $50 per pupil.
 Several caveats apply to the cost data used. At the time of writing, the most comparable cost estimates we have across operators, in a uniform template, are their original budgets, rather than actual expenditures. Five operators also submitted additional (self-reported) data to the evaluation team on actual expenditures, in various formats. More Than Me reports total expenditure per child in the first year was $255.55 (recurring: $220.55, start up cost: $34.95); Bridge International Academies reports total expenditure per child in the first year was $662.74 (recurring: $321.15, start up cost: $341.59); Street Child reports a total expenditure per child in the first year of $48.48; Omega reports total expenditure per child in the first year was $39.75 (recurring: $39.10, start up cost: $0.65); and Rising Academies reports total expenditure per child in the first year was $270 (recurring: $229.50, start up cost: $40.50).
 In Figure 1, the blue bar represents the average difference in test scores from one grade to the next in comparison schools. The green bar also includes the impact of the program.
 All results in Figures 1 & 2 are p < 0.01. Small p values indicate statistical significance: that the observed effect of PSL is not likely to have occurred by chance.
 For Bridge International Academies, the cap was 45-55 students per class; for all other operators, the cap was 65 students per class.
 *= p < 0.10, ** = p < 0.05, and *** = p < 0.01. Small p values indicate statistical significance: that the observed effect of PSL is not likely to have occurred by chance. Statisticians generally agree that p values less than 0.05 indicate a true effect size different from zero.
 Operators reported their original (pre-spending) per-pupil budgets (top bars). Five operators also submitted additional (self-reported) data to the evaluation team on actual expenditures, in various formats (bottom bars). These costs reflect both costs that operators say are startup costs and the operators’ year 1 costs. See Footnote 4 on page 2 of this brief, regarding several caveats that apply to the budget and cost data used in this figure.
 These treatment estimates adjust for baseline differences in schools. The estimates also include a Bayesian adjustment, which averages the overall effect and the operator’s individual effect, weighted according to the operator’s number of schools.
 Some operators had no schools with baseline class sizes above the class caps.