Resnik DB, Tyler AM, Black JR, et al. Authorship policies of scientific journals. Journal of Medical Ethics 2016;42(3):199-202
The authors analysed the authorship policies of a random sample of 600 journals from the Journal Citation Reports database. 62.5% of the journals they sampled had an authorship policy. Journals from the biomedical sciences and social sciences/humanities were more likely to have an authorship policy than journals from the physical sciences, engineering or mathematical sciences. A significant finding of the study is that none of the journals with authorship policies addressed the use of equal contribution statements.