Author ordering in scientific research: evidence from scientists survey in the US and Japan

This paper examines what drives author ordering in scientific research. We first discussa theoretical framework for the choice between alphabetical ordering and relative-contribution-based ordering and develop hypotheses, focusing on the nature of research, in particular, the importance of collaboration in the context of incomplete contract, the measurement cost of contribution-based ordering and the role of a principal investigator (PI). Our empirical examinations, based on the new large scale original scientists' surveys in the US and Japan, show the supporting results. In particular, an alphabetical ordering is more likely to be used when the research is theoretical and has less empirical component and when the team size is large and not co-located. The variation of research method goes a long way in explaining the variation of the use of alphabetic ordering across fields (mathematics and economics vs. the others) as well as its variation within a field. We also find that PI or Co-PIs are more likely to exist when the project uses more resources as well as when the team is more heterogeneous. Finally, we confirm that author ordering sends two signals in contribution based ordering, the first author for the largest research contribution and the last author for the PI ( or Co-PI).