The ancient practice of borrowing on personal security—meaning that in case of default the debtor or a family member had to “enter the house” of the creditor and serve him for some time or for life
[1]—finds a modern equivalent in charges levied on the future wages of the debtor. Why people ceased using voluntary personal securities to safeguard credit?
[1] See, for instance, Silver (1995, pp. 117-122). This interpretation seems now more widely accepted that previous ones (e.g., Finley, 1965) that consider that many of these contracts were simple sale of labor.