  This paper analyzes the evolution of coauthorship in Spain in the social
sciences between 2000 and 2013. The goal is to explore to which extent
limitations on the number of coauthors established by Spanish national
evaluation agencies are justified. The analysis of 11681 papers authored by
researchers affiliated to Spanish institutions in 20 subject categories of the
social sciences reveals that there is no inflation in the number of authors,
team size is similar to that found in foreign papers and the number of authors
is dependent on international and institutional collaboration. With the
exception of Anthropology and Special Education, in no area the average of
authors by paper is higher than four. However, papers with a higher number of
authors receive more citations. Overall, our results suggest that there is no
justification on limiting the number of coauthors in publications,
acknowledging that their inclusion in the criteria employed by Spanish
evaluation agencies is to prevent honorary authors. Such limitation endangers
institutional and international collaboration, and consequently, high impact
research.
