On the occasion of the 65th birthday of Prof. Dr. Rudolf Vetschera, colleagues from all over the world contributed their works in order to compile an issue that is meant as a tribute to his achievements, wisdom, and kindness.

Sharing platforms such as Airbnb provide rich information on the good or service to be exchanged, as well as elaborate mechanisms to protect against fraud. Thus, one could argue that contracts concluded via such platforms achieve a high level of completeness. According to economic theory, the...