Joshua D. Angrist, Erich Battistin and Daniela Vuri show in the Vol.9,No4 2017 ed of the American Economic Journal of Applied Economics that Southern Italy teachers are more likely to manipulate student scores. It is not suggested in the article but I claim that it is certainly an effect of the mafia’s influence in the area : many students have parents in the mafia or, in the higher levels (here the study discussed deals solely with primary schools), are maybe themselves part of it. It is thus “peligroso sporgersi” for teachers who may want to favour these students as a preventive response. Hence it seems impossible to draw policy conclusions from that paper until the issue of mafia is seriously tackled. The failure of class size reduction to enhance learning in Italy can likewise be explained by the parallel economic system of the mafia, which is all but an incentive to study.
The issue is obviously similar in many underprivileged suburbs all around the world where the illegal economy competes with the traditional meritocratic system. It would be better to end compulsory school attendance and keep only national exams at each level to avoid presence of noisy and undisciplined students that slow down the others (article in French).