The U.S. ranks 19th out of 30 countries in the outcomes it gets from its investments in education, according to "The Efficiency Index: Which education systems deliver the best value for the money?, " a report released Thursday by GEMS Education Solutions, a London-based education consultancy.
Finland, Korea, and the Czech Republic were deemed the most educationally efficient countries in the study, which is based on 15 years of data from members of the Organization for Economic Cooperation and Development.
Researchers used composite achievement results from the 2012 Programme for International Student Assessment, or PISA, as the performance metric, and weighed those scores against 63 "inputs, " or factors that could influence educational outcomes, such as teaching materials and technology, the quality of school buildings, and teacher training.
Only two factors in the statistical model were found to have an impact on PISA results: changes in teachers' salaries and class size.
The United States would have to reduce teacher salaries about 5 percent below their current average of , 460 and increase class size by 10 percent—to nearly 17 students per teacher—to be optimally efficient, the researchers said.
The performance differences among the countries "cover less than a quarter of the variability in outcomes that are observed between schools and pupils, " acknowledged Andreas Schleicher, the director for education and skills, and special advisor on education policy to the secretary-general of the OECD, in his introduction to the report.
For instance, socioeconomic differences among students in various countries were not considered, said Adam Still, a co-author of the report and an education finance and development specialist for GEMS, in a phone interview. Rather, they focused on factors that education policymakers could influence, he said.
However, Schleicher wrote that the efficiency index is important because it "breaks the silence on the efficiency of educational services, " and raises questions about what is possible for improving educational return on investment during tight budgetary times. Some of the countries with the highest efficiency ratings do not pay the highest salaries, nor do they have the lowest student-teacher ratios.
