Teachers are the most important school resource. In every country, teachers' salaries and training represent the greatest share of expenditure on education; and this investment in teachers can have significant returns. Research shows that being taught by the best teachers can make a real difference in the learning and life outcomes of otherwise…

The PISA studies in recent years have disclosed fundamental problems in the educational and training systems of many countries. According to the studies, it seems that simply increasing the education expenditures per pupil regularly does not sufficiently achieve better pupil performances. This "input-oriented" policy does not have any…

In the United States, evidence abounds on the effects of expenditures and class size on student achievement, but often it is controversial. In other parts of the world, hard evidence is not as easy to come by, mostly because of data limitations. But over the years, testing agencies have started to collect data on student performance and family…