Research Focuses
The chair’s research profile spans five areas of German, European, and international private law.
European Private Law
European private law is undergoing profound change as a result of the requirements of Union law. Union private law is created by the European legislature and is being increasingly expanded and refined by the European Court of Justice (ECJ). This incremental approach lacks the coherent systematic framework found in national civil law systems (e.g., the German Civil Code [BGB] of 1900, the French Civil Code [Code civil] of 1804). Another difference concerns the enforcement of rights: While in Germany the standardization of procedural law (ZPO, GVG) served as the foundation, EU law relies on the courts of the member states, whose procedural rules remain largely unstandardized. (Important issues such as jurisdiction, recognition, and enforcement are, however, standardized under EU law.)
Particular attention is paid to the directives and regulations governing contract law, tort law, and commercial law, as well as to methodology and the case law of the European Court of Justice. A defining work is the 600-page monograph “European Jurisdiction in the Field of Civil Law.” The work has been widely reviewed (including in the FAZ), was cited in the British House of Commons, and referenced in the opinions of Advocates General.
Against this backdrop, key questions arise: What are the consequences of EU law superseding national civil law? What methodological implications does this have for the interpretation of the German Civil Code (BGB)? What role does the European Court of Justice play as a de facto federal civil court?
Selected Publications
- Court of Justice of the European Union
Encyclopedia of Private International Law, Elgar 2017, 484 - European Jurisdiction in the Field of Civil Law
Mohr Siebeck 2012 - Referral Practices of EU Member States
EuR 2012, 392
Private International Law and Procedural Law
Another area of focus concerns cross-border matters. These include private international law (PIL)—also known as conflict of laws—as well as international civil procedure law (ICPL). Private international law determines which law applies to a case with a foreign element. International civil procedure law determines which court has jurisdiction and how foreign judgments are recognized and enforced.
Most conflict-of-laws issues in commercial, family, and inheritance law are now governed by EU law. Through Rome I, Rome II, Rome III, the EU Succession Regulation, and others, the EU legislature has largely replaced the EGBGB, which was formerly a purely German area of law.
A key project is the Hay/Rösler textbook, “International Private Law and Civil Procedure,” a new edition of which is currently in preparation. Using 229 cases, it covers all areas of private international law (IPR) and international civil procedure law (IZVR)—beginning with international civil procedure law, followed by the general conflict-of-laws rules and the connecting factors of the individual areas of law.
In addition, there are contributions to the Encyclopedia of Private International Law as well as on the freedom to choose the applicable law in international divorce law (RabelsZ 78 [2014], 155).
Selected Publications
- How Much International Element Is Required for a Choice-of-Court Agreement in Civil and Commercial Matters Under Article 25 of the Brussels Ia Regulation?
FS Gounalakis, Nomos 2025, 177 - Hay/Rösler, International Private Law and Civil Procedure
C.H. Beck, 5th ed., 2016
Comparative Law and Legal Harmonization
Comparative law research examines the contrast between civil law (Continental European) and common law (Anglo-American). Common law has no codified civil law. The law is further developed by leading judges. Where statutes do exist (e.g., the UCC, the Sale of Goods Act 1979), they remain fragmentary—case law dominates. The ratio decidendi of higher courts (stare decisis) is binding. The focus is on methodological peculiarities such as prospective overruling.
The global harmonization of sales law is also of great importance, particularly the UN Convention on Contracts for the International Sale of Goods (CISG). Notable works include the essay“Seventy Years of the Law of Sale of Goods by Ernst Rabel”(RabelsZ 70 [2006], 793). Legislative advisory work is also relevant, such as the comprehensive reform of Vietnamese civil law (Civil Code of 2015).
Selected Publications
- Changes in Case Law in U.S. Private Law
RabelsZ 79 (2015), 250 - The Effect of Precedents in German Civil Procedure Law
ZZP 126 (2013), 295
Media and Communications Law
Media and communications law is undergoing rapid change: digitization, industry convergence, new communication formats, shifting notions of privacy, user-generated content, the decline of traditional gatekeepers, and an increase in cross-border issues. These developments necessitate treating media law as a distinct field of law.
The Institute for Media and Communications Law (IMKR) was founded in 2015. Prof. Rösler is a co-founder. The IMKR covers, among other things, press, broadcasting, and information law; data protection law; and aspects of intellectual property and technology law.
Selected Publications
- The Limits of Copyright Law Regarding Leaked Government Documents
ZUM 2017, 758 - Dignitarian Posthumous Personality Rights
Berkeley J. Int’l L. 26 (2008), 153
Civil Law, Commercial and Business Law
A key area of focus is commercial law, particularly contract law. Notable contributions include his work on the doctrine of the basis of a transaction (JuS 2004–2005) and the article “Fraudulent Intent in Contract Law” (AcP 207 [2007], 564 ff.), which has been cited in landmark decisions of the Federal Court of Justice (BGH).
In addition, intensive research is conducted on the intersections between German civil law and EU law, particularly regarding internal market integration, consumer protection, and anti-discrimination law. In commercial law, the focus is on comparative law and the UN Convention on Contracts for the International Sale of Goods. Other areas of focus include competition law and copyright law.
Selected Publications
- Protection of the Weaker Party in European Contract Law
RabelsZ 73 (2009), 889 - Fraudulent Intent in Contract Law
AcP 207 (2007), 564