The purpose of this chapter is to test whether the patterns observed in the qualitative study hold statistical significance across a larger sample of firms in the Prato district. We construct and empirically assess a conceptual model in which supplier collaboration and retailer collaboration function as independent variables, relational learning acts as a mediating mechanism, and sustainable supply chain performance constitutes the dependent outcome. This model captures the idea that supply chain sustainability is not the direct product of collaboration alone, but the result of learning processes that emerge within those collaborative relationships. To test this hypothesis, we employ structural equation modeling (SEM), a statistical approach particularly well suited to this type of analysis. SEM allows us to assess both the measurement properties of our constructs and the causal pathways among them.