The h -index has become a widely used metric in academic evaluation, influencing hiring, promotion, and funding decisions across disciplines. Its appeal lies in its simplicity, combining productivity and citation impact into a single number. However, the h -index does not account for differences in author contribution, granting full citation credit to all coauthors regardless of their role. This practice inflates credits and distorts—sometimes dramatically—researchers’ rankings, particularly in fields with large collaborative teams. While many variants of the h -index have been proposed to address this issue, none have achieved widespread adoption or integration into platforms like Google Scholar. In this study, we examine h -index data from 20 researchers across two contrasting fields and evaluate four modified indices that adjust for coauthorship. Among these, the s -index—a modified harmonic credit-based model—emerges as a promising companion to the h -index. The s -index is conceptually straightforward, computationally simple, and adaptable to both contribution-based and alphabetical author listings. It acknowledges the added value of each coauthor while distributing credit proportionally to their contribution. Our findings show that the s -index functions as a field-neutral credit equalizer, preserving simplicity while improving fairness. We propose that Google Scholar display the s -index alongside the h -index, enabling the calculation of a Research Leadership Share (RLS), defined as the ratio of s -index to h -index. A lower RLS would reflect greater coauthorship dilution, helping to discourage token authorship and encourage equitable credit practices. By aligning credit allocation with ethical authorship norms, the s -index supports a more just and transparent system for evaluating scholarly contributions.
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