Self-citations — those where authors cite their own works — account for a significant portion of all citations. These self-references
may result from the cumulative nature of individual research, the need for personal gratification, or the value of self-citation
as a rhetorical and tactical tool in the struggle for visibility and scientific authority. In this article we examine the
incentives that underlie self-citation by studying how authors’ references to their own works affect the citations they receive
from others. We report the results of a macro study of more than half a million citations to articles by Norwegian scientists
that appeared in the Science Citation Index. We show that the more one cites oneself the more one is cited by other scholars.
Controlling for numerous sources of variation in cumulative citations from others, our models suggest that each additional
self-citation increases the number of citations from others by about one after one year, and by about three after five years.
Moreover, there is no significant penalty for the most frequent self-citers — the effect of self-citation remains positive
even for very high rates of self-citation. These results carry important policy implications for the use of citations to evaluate
performance and distribute resources in science and they represent new information on the role and impact of self-citations
in scientific communication.