Die lex commissoria im neuen Licht oder verhaltensökonomische Streifzüge im klassischen römischen Recht

The paper focuses on the so called lex commissoria in purchase and sale agreements, a clause that allowed for a transfer of a good delivered to the creditor by virtue of a non-performance of contractual obligations. Speculating on the discipline according to Roman experience, in particular on the suspensive and termination effect of an obligation, on the impact on social relationships, the author elaborates on the case-law interpretation obtained when searching for practical solutions rather than dogmatically correct ones.