Proportionality in Private Law

Proportionality is not exclusively a public law concept but also plays an important role in private law. A May 2022 conference held at the Max Planck Institute for Comparative and International Private Law explored this topic intensively, examining the private law forms and functions of proportionality from the perspectives of multiple jurisdictions. The findings of the conference are now available in a recently published edited volume.

The conference proceedings, authored in English, have been edited by Ben Köhler, research fellow at the Institute, and Franz Bauer, research associate at the Institute. In the two introductory chapters of the volume, the editors provide an overview of the relevant materials and identify typical characteristics and functions of the concept as encountered in private law. The subsequent contributions have been authored by junior researchers based in various legal jurisdictions and stitch together theoretical, constitutional and comparative perspectives. The entries are grouped under three main headings. The first part focuses on the constitutional and theoretical foundations of proportionality in Germany and the USA. The entries in the second part examine the concept’s potential in three specific areas of European private law: contract law, intellectual property law, and private international law. The final part looks at the possible functions of proportionality in the context of procedural issues.

Considered as a whole, the contributions collected in the volume demonstrate not only the multidimensional nature of proportionality in private law but also the many commonalities and connecting lines across jurisdictions and legal contexts.

© Max Planck Institute for Comparative and International Private Law