It has been often noted (McDowell and Melvin, 1983; Barnett et al., 1988; Piette and Ross, 1992; Sutter and Kocher, 2004) that the share of co-authored papers in economics has been increasing steadily. The purpose of this study is to investigate some of the theories as to why co-authorship has been increasing in the economics profession. Using data on the publication records of faculty at 129 US colleges and universities that offer doctoral degrees in Economics, Poisson and logit regression models are estimated to explain co-authorship. Results indicate that the likelihood of co-authorship is greater for papers that combine quantitative analysis with another field and for papers published in higher quality journals. Further, co-authorship appears to differ in the many subfields of economics, with the field of Economic History and History of Thought (Journal of Economic Literature (JEL) categories N and B) to be the least likely to co-author and the fields of Financial Economics (JEL category G) and Agricultural and Natural Resource Economics (JEL category Q) to be the most prone to co-authorship.
