2014 Elsevier Inc. All rights reserved. The article summarizes the economist's notion of a market and relative price in terms of trade of goods or services in both exchange and planned economies. Pricing efficiency and characteristics of efficient price movement through time are covered. The article concludes with a discussion of the role of the quantity of money or other macroeconomic factors in arriving at the level of prices. Price is the basic signal of exchange in economic systems. Price is found (discovered) in a market where buyers (demanders) and sellers (suppliers) of a commodity come together to negotiate an exchange at a price.
