- Long-run
In economic models, the long-run time frame assumes no fixed
factors of production . Firms can enter or leave themarketplace , and the cost (and availability) of land, labor,raw materials , andcapital goods can be assumed to vary. In contrast, in the "short-run " time frame, certain factors are assumed to be fixed, because there is not sufficient time for them to change. This is related to thelong run average cost (LRAC) curve, an important factor inmicroeconomic models.A generic firm can make these changes in the long-run:
*Enter an industry
*Increase its plant
*Decrease its plant
*Leave an industry"Long run marginal cost" ("LRMC") refers to the cost of providing an additional unit of service or
commodity under assumption that this requires investment in capacity expansion. LRMC pricing is appropriate for bestresource allocation , but may lead to a mismatch between operating costs and revenues.In macroeconomic models, the long run assumes full factor mobility between economic sectors, and often assumes full
capital mobility between nations.The concept of "long run cost" is used in cost-volume-profit analysis and product mix analysis.
A famous use of the phrase was by
John Maynard Keynes , who said in dry humor, "In the long run, we are all dead."ee also
*
Long run average cost
*Short-run
Wikimedia Foundation. 2010.