Consumer psychology refers to how people think and act within an economic role in market exchange. However, we know little about how consumers actually perceive these roles, or how they understand markets and economic activity more broadly. That is, we lack an understanding of the economic reasoning of non‐expert consumers, how it departs from formal economic reasoning, and why. The current paper is intended to address this gap. We provide an integrative review of research on lay economic reasoning that consistently reveals how differently lay consumers and economists think about markets. We propose a unifying mental model to explain these divergences. Suggest why it is reinforced by what lay consumers observe (and do not observe) through firsthand marketplace experience, and note its potential evolutionary basis. We then highlight how understanding lay economic reasoning can not only help explain a wide array of marketplace phenomena, but also provide a novel lens to help advance, generate, and better integrate theory across many active literatures within consumer psychology. Without markets, there are no consumers and there is no marketing. We therefore call for consumer psychologists to take ownership of the study of lay economic reasoning and make markets more central to marketing scholarship.