In economics, the marginal product or marginal physical product of an input to production during a specific time period is as follows, assuming that no other inputs to production change: U.S. Economic Calendar Economics at the Open Directory Project Economics textbooks on Wikibooks The Economists Economics A-Z Institutions and organizations Bureau of Labor Statistics - from the American Labor Department Center for Economic and Policy Research (USA) National Bureau of Economic Research (USA) - Economics material from the organization...

marginal product of X used in producing Y = ΔY/ΔX = (the change of Y)/(the change of X).

In neoclassical economics, this is the mathematical derivative of the production function. Note that the "product" (Y) is typically defined ignoring external costs and benefits. In the "law" of diminishing marginal returns, the marginal product of one input is assumed to fall as long as some other input to production does not change. Neoclassical economics refers to a general approach (a metatheory) to economics based on supply and demand which depends on individuals (or any economic agent) operating rationally, each seeking to maximize their individual utility or profit by making choices based on available information. ... In mathematics, the derivative is one of the two central concepts of calculus. ... In microeconomics, a production function expresses the relationship between an organizations inputs and its outputs. ... An externality occurs in economics when a decision (for example, to pollute the atmosphere) causes costs or benefits to stakeholders other than the person making the decision. ... In economics, diminishing returns is the short form of diminishing marginal returns, the concept that, as more of an input is applied, each additional unit produces less and less additional output. ...

In the neoclassical theory of the competitive markets, the marginal product of labor equals the real wage. Similarly, under the same conditions, the marginal product of capital equals its rate of return. But there have been severe criticisms of this theory. Perfect competition is a model in economic theory. ... In economics, the distinction between nominal and real numbers is often made. ... In politics a capital (also called capital city or political capital — although the latter phrase has an alternative meaning based on an alternative meaning of capital) is the principal city or town associated with its government. ... In economics, the profit rate refers to the relative profitability of an investment project or of an capitalist enterprise or for the capitalist economy as a whole. ... The capital controversy refers to a debate in economics concerning the nature and role of capital goods (or means of production) that occurred during the 1960s, largely between economists such as Joan Robinson and Piero Sraffa at the University of Cambridge in England and economists such as Paul Samuelson and...