We investigate the potential balance between some teacher characteristics, particularly teachers’ satisfaction and different measures of pupils’ performance (average students’ test scores and percentage of students achieving basic standards of learning in mathematics), in order to optimize the outputs of the Spanish education system. Our contribution to the existing literature is twofold: on the one side, we provide estimates on the balance between teachers’ effectiveness and fourth grade students’ performance in Spain, by using recent survey data from the program on Trends in International Mathematics and Science Study; on the other side, we implement a novel methodology which allows optimizing simultaneously a set of indicators of the educational system outputs, to the extent that our empirical approach revealed the existence of some degree of conflict among the outputs under scrutiny. These analyses provide empirical evidence of the importance of simultaneously analysing different indicators of the performance of the education system and the need to invest in teachers’ satisfaction as a motivation mechanism for improving national educational achievement, at least in primary education. Additionally they bring attention into the harmful impact of some education policy measures taken as a consequence of the economic crisis, as, e.g. the delay in the replacement of teachers, which entails the lack of teachers at schools to cover all lessons.