In economics, iminishing returns is also called diminishing marginal returns or the law of diminishing returns. According to this relationship, in a production system with fixed and variable inputs (say factory size and labor), beyond some point, each additional unit of variable input yields less and less additional output. Conversely, producing one more unit of output costs more and more in variable inputs. This concept is also known as the law of increasing relative cost, or law of increasing opportunity cost. Although ostensibly a purely economic concept, diminishing marginal returns also implies a technological relationship. Diminishing marginal returns states that a firm's short run marginal cost curve will eventually increase.