zinskauf
{{Short description|Medieval financial instrument}}
Zinskauf ({{IPA|de|ˈt͡sɪns.kaʊ̯f|}}, "purchase interest") was a financial instrument, similar to an annuity, that rose to prominence in the Middle Ages.{{Cite book|title = Reforming the Morality of Usury: A Study of the Differences That Separated the Protestant Reformers|last = Jones|first = David|publisher = University Press of America|year = 2003|pages = 53}}{{cite book|last1=Doherty|first1=Sean|title=Theology and Economic Ethics: Martin Luther and Arthur Rich in Dialogue|page=55|access-date=2 December 2014 |url = https://books.google.com/books?id=d45tAwAAQBAJ&pg=PA55&}}{{cite book|last1=O'Donovan|first1=Oliver|title=From Irenaeus to Grotius: A Sourcebook in Christian Political Thought, 100-1625|page=584}} The decline of the Byzantine Empire led to a growth of capital in Europe,{{cn|date=May 2024}} so the Catholic Church tolerated zinskauf as a way to avoid prohibitions on usury. Since zinskauf was an exchange of a fixed amount of money for annual income it was considered a sale rather than a loan. Martin Luther made zinskauf a subject of his Treatise on Usury[http://www.godrules.net/library/luther/NEW1luther_d4.htm Treatise on Usury] full text online and his Sermon on Trade and Usury{{cite web|title=Martin Luther's Sermon On Trade and Usury|url=http://www.godrules.net/library/luther/NEW1luther_d2.htm}} and criticized clerics of the Catholic Church for violating the spirit if not the letter of usury laws.
In one historian's analysis:
{{Quote|This financial transaction, for which no direct equivalent exists in modern finance, essentially was a contract in which the rights to use a piece of land or other property were sold in exchange for fixed payments over a specified period of time. To avoid the appearance of usury, the creditor in this transaction was regarded as the buyer who purchased a fixed income from the debtor, who then merely was considered to be the seller of a predetermined stipend." Luther viewed this practice to be usurious since at the expiration of the zinskauf the creditor had increased in net-worth without ever engaging in labor.}}