Are Italian research assessment exercises size-biased?

Research assessment exercises have enjoyed ever-increasing popularity in many countries in recent years, both as a method to guide public funds allocation and as a validation tool for adopted research support policies. Italy's most recently completed evaluation effort (VQR 2011-14) required each university to submit to the Ministry for Education, University, and Research (MIUR) 2 research products per author (3 in the case of other research institutions), chosen in such a way that the same product is not assigned to two authors belonging to the same institution. This constraint suggests that larger institutions, where collaborations among colleagues may be more frequent, could suffer a size-related bias in their evaluation scores. To validate our claim, we investigate the outcome of artificially splitting Sapienza University of Rome, one of the largest universities in Europe, in a number of separate partitions, according to several criteria, noting significant score increases for several partitioning scenarios.