marginal rate of technical substitution(redirected from Technical rate of substitution)
marginal rate of technical substitutionthe ratio of the MARGINAL PHYSICAL PRODUCTS of two FACTOR INPUTS in the production process, that is, the amount by which it is possible to reduce factor input X and maintain output by substituting an extra unit of factor input Y. It is measured by the slope of the producer's ISOQUANT CURVE. In order to minimize his production costs, a producer must equate the ratio of the marginal physical products of the two factor inputs (shown by the isoquant curve) to the ratio of their factor prices (shown by the ISOCOST LINE). See ISOQUANT MAP.
Collins Dictionary of Economics, 4th ed. © C. Pass, B. Lowes, L. Davies 2005