MARGINAL PRODUCT: The change in the quantity of total product resulting from a unit change in a variable input, keeping all other inputs unchanged. Marginal product, usually abbreviated MP, is found by dividing the change in total product by the change in the variable input. Marginal product lies at the very foundation of the analysis of short-run production and the subsequent explanation of the law of supply and the upward-sloping supply curve, using the law of diminishing marginal returns. See also | total product | output | input | variable input | fixed input | average product | marginal cost | law of diminishing marginal returns | average-marginal rule | total-marginal rule | short-run production | marginal physical product |
