»Transferees’ Rights in the Event of Transfers of Undertakings. Concerning the Boundaries of Labour Rights under European Union Law«: Transfers of undertakings regulation is deemed applicable by the ECJ in case the economic entity retains its identity. The question arises why the ECJ chose this criterion. This comes down to »cost-benefit equivalency«, i.e. the transferee being able to continue the business. This seems all the more compelling when analysing transfers of undertakings regulation in terms of the requirements of legal methodology and European primary law. These insights can help solve complex legal problems.