Since their fi rst implementation in 2000, the PISA studies have attracted public attention and spurred the demand for institutional changes in schooling systems. The introduction of standardized student tests and of incentives for schools and teachers are notable examples of such institutional changes. This paper examines the eff ects of these particular developments. Identifi cation is based on within-country variation between PISA 2000 and PISA 2009. The results indicate that comparing schools by means of standardized student test results is a promising measure, while evaluating teachers this way decreases the overall performance of a schooling system. The discussion provides possible explanations for these ambiguous fi ndings.