Maud Minois (University Paris Descartes) has published earlier this year a monograph presenting her Research on Characterization in the Private International Law of Obligations (Recherche sur la qualification en droit international privé des obligations).
The author has provided the following English abstract:
Characterization is traditionally presented as a tool used to ensure legal certainty and rationality of law. We observe, however, that this is not necessarily the case in the context of private international law. For a long time, the lex fori characterization has dominated the international scene, so that it may appear as the most suitable model of qualification. But it does reveal certain shortcomings when applied to contract and tort law. The diversification of sources of the law as well as the rise of autonomous characterizations established by the Court of Justice of the European Union add further complexity to the picture. An efficient model for characterization is needed to restore coherence in private international law. In order to elaborate such a model, two axes of study must be explored successively. First, the model must suit the specificities of private international relations. Second, once proof has been offered for the thesis that autonomous characterization best answers this demand, the question of its generalization should be addressed. It appears that an efficient use of the autonomous qualifications can be made not only at the level of European private international law, but on the contrary, can be extended to private international law of conventional as well as of national sources. On the other hand, this model, as it specifically applies to private international relations has no place in substantive law.
More details are available here, including free access to the table of contents and the introduction of the book.