Schaffung und Akzeptanz einheitlichen Privatrechts in Europa - Lehren aus der Anwendung des UN-Kaufrechts für ein Europäisches Vertragsrecht

The present article (written in German) discusses whether legal instruments creating uniform private law - either by way of a Convention (a treaty under public international law) or in some other form - should preferably be designed as "opt in" instruments (meaning that the uniform law text will only apply if the parties to a contract provide for its application by way of a choice-of-law clause), or rather as "opt out" instruments (meaning that the text will apply ipso iure, provided the parties to the contract have not opted out of its application).
This discussion, which has been going on for decades, has in recent years gained new impetus because of the current preparations for an "optional instrument" to (potentially) be enacted by the European Union at some time in the future. The present study suggests a new approach to this question by adopting an institutional economics perspective and drawing on the practical experiences made with the United Nations Convention on Contracts for the International Sale of Goods of 1980 (CISG): This Convention, which ranks as the most successful uniform private law instrument in history, is designed as an "opt out" instrument. By focusing on the interest that various groups (companies, their lawyers, judges and arbitrators, States) have demonstrated with respect to the possibility to opt out of the CISG, the article tries to outline which preferences these groups have when it comes to an opt in or opt out design of a future European Contract Law (the "optional instrument"), and makes suggestions for a design that would be accepted by a majority of players.