Prozbul - from Rabbinical Council of America Posting

"The rationale behind the historic takkanah (or decree) should be very familiar to us, faced as we are with the current credit crisis that has confounded contemporary financial markets. In the run up to the Sabbatical year of that time, Hillel saw that credit was drying up because potential creditors saw little means of collecting on their loans after the Sabbatical year had come and gone. The result would be a catastrophe for the poor, if not a meltdown of the entire economy. So Hillel found a legitimate way (actually it was implicit in the Torah's own formulation of the Sabbatical laws, but he made the provision explicit) to have the rabbinic courts of his day act as guarantors of outstanding loans (or more precisely to take over the loans, so as to collect them on behalf of the creditors when they came due.) '