Trust has long been recognized as an important component of marketing systems. However, while macromarketing researchers argue that a lack of trust in business can impact other components of marketing systems, very few empirical studies in marketing investigate the determinants or outcomes associated with this type of trust. Accordingly, we begin with the premise that trust in major corporations is a critical, micro-level attitude that affects the performance of a marketing system. Then, we investigate the factors that influence trust in major corporations by analyzing how perceptions of government involvement in business, political ideology, and other attitudinal and demographic variables affect trust. Using hierarchical linear modeling, we find that trust has a curvilinear relationship with perceptions of free-market competition, in which too much trust, or too little, leads to negative perceptions - trust plays a critical mediating role in constructing beliefs about free markets. Additionally, we show that macroeconomic variables influence the first stage of attitude formation toward major corporations, with gross domestic product (GDP) per capita and foreign direct investment (FDI) acting as moderators in our analysis. Overall, the multi-level moderated-mediation model used in this research embodies a true systems approach to the analysis of marketing systems by demonstrating how the economic outcomes of marketing systems (e.g., GDP and FDI) can also have feedback effects on participants within a marketing system.