FIXED INPUT: An input in the production of goods and services that does not change in the short run. A fixed input should be compared with a variable input, an input that DOES change in the short run. Fixed and variable inputs are most important for the analysis of short-run production by a firm. The best example of a fixed input is the factory, building, equipment, or other capital used in production. The comparable example of a variable input would then be the labor or workers who work in the factory or operate the equipment. In the short run (such as a day or so) a firm can vary the quantity of labor, but the quantity of capital is fixed.

     See also | input | variable input | short-run production | labor | capital | factors of production | total product | average product | marginal product |