Optimum class size. Testing lazear’s theorem with intermediate mathematics scores in Polish secondary schools

The paper is directed at testing Lazear’s proposition which argues that educational outcome depends on the non-uniformity of distribution of knowledge and skills of students and on class size. Lazear asserts that students’ performance achieves its maximum when students are segregated by skills and behaviour. Using the 2010 data (mathematics scores in gimnazjum and maturity exams), we corroborate this theorem. We also demonstrate that improved teaching conditions in Polish primary schools and gimnazjums, i.e. lower class sizes, better salaries of teachers and higher unit costs did not result in an increased educational outcome as measured by the final examination scores in primary and secondary schools between 2006 and 2011.