Arnold Carl Harberger (born July 27, 1924) is an American economist. His approach to the teaching and practice of economics is to emphasize the use of analytical tools that are directly applicable to real-world issues. His influence on academic economics is reflected in part by the widespread use of the term "Harberger triangle" to refer to the standard graphical depiction of the efficiency cost of distortions of competitive equilibrium. His influence on the practice of economic policy is manifested by the high positions attained in national agencies such as central banks and ministries of finance, and in international agencies such as the World Bank.