New Bradfordian laws equivalent with old Lotka, evolving from a source-item argument

Abstract

Based on the duality techniques in a previous paper (L. Egghe, The duality o f informetric systems with applications to the empirical laws), we study general relationships between Bradfordian and Lotka laws. This results in new Bradfordian laws which are B equivalent with the well-known Lotka laws $(n) = - (a > 1). The new method also sheds some light on the question why a < 2 i s more common than a > 2. Also, the general law of Leimkuhler, as found by Rousseau, i s reproved and shown to be equivalent with the above mentioned laws. Fitting methods are applied and give close results.