Well for one thing, in my anecdotal scenario, such transactions acrue no interest. It was the kind of debt anyone could incur and payback. Money lenders aren't

Well for one thing, in my anecdotal scenario, such transactions acrue no interest. It was the kind of debt anyone could incur and payback. Money lenders aren't under any obligation to give you a loan of any size. In that village there was a self-perpetuating obligation to provide the debt. As for how it would scale, I don't know. Is the structure and culture of western urban society the only form possible?