Bilateral Co-authorship Indicators Based on Fractional Counting

Abstract Purpose In this contribution we provide two new co-authorship indicators based on fractional counting. Design/methodology/approach Based on the idea of fractional counting we reflect on what should be an acceptable indicator for co-authorship between two entities. From this reflection we propose an indicator, the co-authorship score, denoted as cs, using the harmonic mean. Dividing this new indicator by the classical co-authorship indicator based on full counting, leads to a co-authorship intensity indicator. Findings We show that the indicators we propose have many necessary or at least highly desirable properties for a proper cs-score. It is pointed out that the two new indicators can be used for countries, but also for institutions and other pairs of entities. A small example shows the feasibility of the co-authorship score and the co-authorship intensity indicator. Research limitations The indicators are not yet tested in real cases. Practical implications As the notions of co-authorship and collaboration have many aspects, we think that our contribution may help policy management to take yet another aspect into account as part of a multi-faceted description of research outcomes. Originality/value The indicators we propose cover yet another aspect of co-authorship.