McChesney, Fred S.; Shughart, William F.; Haddock, David D. - In: Economic Inquiry 42 (2004) 4, pp. 706-716
As stated originally, the venerable law of one price succinctly describes long-run equilibrium in a perfectly competitive market. The law was later amended, defining a market as the geographic area within which the same thing sells for the same price at the same time, allowance being made for...