This PhD course examines the theoretical assumptions underlying marketing decisions. Every applied decision — pricing, positioning, segmentation, brand management — rests on an implicit theory about the nature of customer behavior, the source of value, brand meaning, and market structure. The course aims to surface these assumptions, evaluate them in light of the relevant theoretical traditions and evidence, and develop the capacity to reason from marketing theory. Core topics include the co-creation of value, consumer decision-making processes, brand equity and meaning, the resource-based view of competitive advantage, relationship and network approaches, and market-shaping theory. By the end of the term, participants are expected to be able to analyze the assumptions on which any marketing strategy rests, and to identify the appropriate theoretical framework for a given decision along with the limits of that framework.