Emily Kadens, Northwestern University School of Law, has published The Medieval Law Merchant: The Tyranny of a Construct at 7 Journal of Legal Analysis 251 (2015). Here is the abstract.
The story of a medieval law merchant has a strong hold on scholars interested in private ordering. Despite numerous historical works demonstrating the falsity of the myth, it continues to be discussed regularly in scholarship as if it were an accurate portrayal of the past. This article tests the law merchant story against evidence about the mechanisms of medieval trade. It suggests that medieval commerce had little space for a specialized law, and that merchants had little need for it because of both the well-developed trading infrastructure and the actions of local governments to ensure the protection of legal rights.Download the article from SSRN at the link.