The effects of citation-based research evaluation schemes on self-citation behaviour

We investigate the changes in the self-citation behavior of Italian professors following the in- troduction of a citation-based incentive scheme, for national accreditation to academic appoint- ments. Previous contributions on self-citation behavior have either focused on small samples or relied on simple models, not controlling for enough confounding factors. The present work adopts a complex statistics model implemented on bibliometric individual data for over 15,000 Italian professors. Controlling for a number of covariates (number of citable papers published by the author; presence of international authors; number of co-authors; degree of the professor's special- ization), the average increase in the number of self-citations per paper following introduction of the national scientific accreditation (ASN) is of 9.5%. The increase is common to all disciplines and academic ranks, albeit with diverse magnitude. Moreover, the increase is sensitive to the rel- ative incentive, depending on the status of the scholar with respect to the ASN. A further analysis shows that there is much heterogeneity in the individual patterns of self-citing behavior, albeit with very few outliers.