Available data and recently developed estimation methods make it possible to assess school performance in terms of a production process, where ’inputs’ of students, teachers, and resources are combined to create a very important ’output’: the cognitive skills of students. This paper estimates the education production function using representative samples of middle-school students in 15 West European countries. The size of teaching classes is a particularly important feature of the educational production process because it can be relatively easily manipulated by policy makers. However, no statistically and economically significant class-size effect is detected by any of the evidence considered in this paper. The results suggest that, at least in the context of the resources and organizational structure of West European lower secondary education systems, expensive across-the-board reduction of class sizes is extremely unlikely to foster student learning.
