Before revision:  Relationships may fail, and given this idosyncratic risk , firms multisource inputs and make costly investments to make relationships with suppliers stronger (less likely to fail). We find that aggregate production is discontinuous in the strength of these relationships.
After revision:  Relationships may fail, and given this idosyncratic risk , firms multisource inputs and make costly investments to make relationships with suppliers stronger . In equilibrium, aggregate production is discontinuous in the strength of these relationships.