A model for the size-frequency function of co-author pairs

Abstract

Lotka’s law was formulated to describe the number of authors with a certain number of publications. Empirical results [S.A. Morris and M.L. Goldstein. JASIST 58(12), 1764-1782, 2007] indicate that Lotka’s law is also valid if one counts the number of publications of co-author pairs.

This paper gives a simple model proving this to be true with the same Lotka exponent if the number of co-authored papers is proportional to the number of papers of the individual co-authors. Under the assumption that this number of co-authored papers is more than proportional to the number of papers of the individual authors (to be explained in the paper), we can prove that the size-frequency function of co-author pairs is Lotkaian with an exponent that is higher than the one of the Lotka function of individual authors, a fact that is confirmed in experimental results.