This dynamic was the basis of the narrow “common bond” requirement in the early credit union movement /model. Basically, social knowledge and social consequences could be leveraged to make someone considered uncreditworthy by people outside of the community legitimately credit worthy to people in the community. If this is a path you’re going down, this post on the evolution of credit unions from that trust-based credit system might be of interest: http://cuhistory.blogspot.com/2011/04/community-building-in-credit-unions.html

“ For a traditionalist, the essence of credit unionism lies in the institution’s ability to use its members’ social knowledge to allocate credit far more efficiently than would be possible for a bank, since the bank has to act upon far less reliable information. A cooperative corporate structure is vital to a credit union’s success, since it ensures that the organization could not become a vehicle for the exploitation of one segment of the community by another, but the scale is equally important for the traditionalist vision. If the members don’t know each other or, even if they do, don’t feel the need volunteer their social knowledge to the credit union, then its ability to allocate credit becomes no different than a bank’s.”