Markets bring buyers and sellers together to exchange goods and services. Markets provide efﬁ cient, self-correcting institutions that provide goods that producers want to sell and consumers want to buy. In this chapter, market equilibrium and mathematical models of supply and demand are introduced and explained. Comparative statics lead to the analysis and understanding of changes in supply and demand. The models explained here provide timely, important, and interesting explanations of real-world events. Price policies including price supports and price ceilings are analyzed, with real-world examples highlighting the consequences of agricultural price policies in low-income and high-income nations.