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Sonnenschein–Mantel–Debreu Theorem
The Sonnenschein–Mantel–Debreu theorem is an important result in general equilibrium economics, proved by Gérard Debreu, , and Hugo F. Sonnenschein in the 1970s. It states that the excess demand curve for an exchange economy populated with utility-maximizing rational agents can take the shape of any function that is continuous, has homogeneity degree zero, and is in accordance with Walras's law. This implies that the excess demand function does not take a well-behaved form even if each agent has a well-behaved utility function. Market processes will not necessarily reach a unique and stable equilibrium point. More recently, Jordi Andreu, Pierre-André Chiappori, and Ivar Ekeland extended this result to market demand curves, both for individual commodities and for the aggregate demand of an economy as a whole. This means that demand curves may take on highly irregular shapes, even if all individual agents in the market are perfectly rational. In contrast with usual a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Equilibrium Theory
In economics, general equilibrium theory attempts to explain the behavior of supply, demand, and prices in a whole economy with several or many interacting markets, by seeking to prove that the interaction of demand and supply will result in an overall general equilibrium. General equilibrium theory contrasts with the theory of ''partial'' equilibrium, which analyzes a specific part of an economy while its other factors are held constant. General equilibrium theory both studies economies using the model of equilibrium pricing and seeks to determine in which circumstances the assumptions of general equilibrium will hold. The theory dates to the 1870s, particularly the work of French economist Léon Walras in his pioneering 1874 work ''Elements of Pure Economics''. The theory reached its modern form with the work of Lionel W. McKenzie (Walrasian theory), Kenneth Arrow and Gérard Debreu (Hicksian theory) in the 1950s. Overview Broadly speaking, general equilibrium tries to give ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Hahn
Frank Horace Hahn FBA (26 April 1925 – 29 January 2013) was a British economist whose work focused on general equilibrium theory, monetary theory, Keynesian economics and critique of monetarism. A famous problem of economic theory, the conditions under which money, which is intrinsically worthless, can have a positive value in a general equilibrium, is called " Hahn's problem" after him. One of Hahn's main abiding concerns was the understanding of Keynesian (Non-Walrasian) outcomes in general equilibrium situations. Biography Early life and education Frank Hahn was born on 26 April 1925 in Berlin to Arnold and Maria Hahn, their roots in German and Czech speaking Jewish communities respectively. Arnold Hahn was a chemist by profession and a writer. Arnold and Maria Hahn with their two sons, Peter and Frank, moved to Prague in 1931 (or possibly 1934) and left for England in 1938. Frank's older brother was Peter Hahn (8 November 1923 – 28 August 2007) who became an eminent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMD Demand Curve
SMD or smd may refer to: Organizations * Science Mission Directorate, a body within NASA * Sharjah Museums Department, former name of the Sharjah Museums Authority * Soil Machine Dynamics, an underwater vehicles company founded by Alan Reece Music * Simian Mobile Disco, an English electronic music duo * '' Slipmatt Dubs'' (born 1967), Breakbeat hardcore series * '' Sacræ Musicæ Doctor'' (Doctor of Sacred Music) Science and technology * Standardized mean difference, a basis for effect size in statistics * Sauter mean diameter, in fluid dynamics * , audio release format developed in Brazil * Service Mapping Description, a proposed standard for describing web services * Stereotypic movement disorder, a motor disorder * Storage Module Device, 1970s CDC disk drives * Surface-mounted device, an electronic component used in surface-mount technology * SMD LED module, a common component of an LED lamp Other uses * Sega Mega Drive, a fourth-generation video game console * Single-membe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vector Calculus
Vector calculus or vector analysis is a branch of mathematics concerned with the differentiation and integration of vector fields, primarily in three-dimensional Euclidean space, \mathbb^3. The term ''vector calculus'' is sometimes used as a synonym for the broader subject of multivariable calculus, which spans vector calculus as well as partial differentiation and multiple integration. Vector calculus plays an important role in differential geometry and in the study of partial differential equations. It is used extensively in physics and engineering, especially in the description of electromagnetic fields, gravitational fields, and fluid flow. Vector calculus was developed from the theory of quaternions by J. Willard Gibbs and Oliver Heaviside near the end of the 19th century, and most of the notation and terminology was established by Gibbs and Edwin Bidwell Wilson in their 1901 book, '' Vector Analysis'', though earlier mathematicians such as Isaac Newton pioneered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utility
In economics, utility is a measure of a certain person's satisfaction from a certain state of the world. Over time, the term has been used with at least two meanings. * In a normative context, utility refers to a goal or objective that we wish to maximize, i.e., an objective function. This kind of utility bears a closer resemblance to the original utilitarian concept, developed by moral philosophers such as Jeremy Bentham and John Stuart Mill. * In a descriptive context, the term refers to an ''apparent'' objective function; such a function is revealed by a person's behavior, and specifically by their preferences over lotteries, which can be any quantified choice. The relationship between these two kinds of utility functions has been a source of controversy among both economists and ethicists, with most maintaining that the two are distinct but generally related. Utility function Consider a set of alternatives among which a person has a preference ordering. A utility fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homothetic Preferences
In consumer theory, a consumer's preferences are called homothetic if they can be represented by a utility function which is homogeneous of degree 1. For example, in an economy with two goods x,y, homothetic preferences can be represented by a utility function u that has the following property: for every a>0: ::u(a\cdot x,a\cdot y) = a\cdot u(x,y) In mathematics, a homothetic function is a monotonic transformation of a function which is homogeneous; however, since ordinal utility functions are only defined up to an increasing monotonic transformation, there is a small distinction between the two concepts in consumer theory. In a model where competitive consumers optimize homothetic utility functions subject to a budget constraint, the ratios of goods demanded by consumers will depend only on relative prices, not on income or scale. This translates to a linear expansion path in income: the slope of indifference curves is constant along rays beginning at the origin. This is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euclidean Vector
In mathematics, physics, and engineering, a Euclidean vector or simply a vector (sometimes called a geometric vector or spatial vector) is a geometric object that has magnitude (or length) and direction. Euclidean vectors can be added and scaled to form a vector space. A '' vector quantity'' is a vector-valued physical quantity, including units of measurement and possibly a support, formulated as a '' directed line segment''. A vector is frequently depicted graphically as an arrow connecting an ''initial point'' ''A'' with a ''terminal point'' ''B'', and denoted by \stackrel \longrightarrow. A vector is what is needed to "carry" the point ''A'' to the point ''B''; the Latin word means 'carrier'. It was first used by 18th century astronomers investigating planetary revolution around the Sun. The magnitude of the vector is the distance between the two points, and the direction refers to the direction of displacement from ''A'' to ''B''. Many algebraic operations on real numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homogenous Function
In mathematics, a homogeneous function is a function of several variables such that the following holds: If each of the function's arguments is multiplied by the same scalar, then the function's value is multiplied by some power of this scalar; the power is called the degree of homogeneity, or simply the ''degree''. That is, if is an integer, a function of variables is homogeneous of degree if :f(sx_1,\ldots, sx_n)=s^k f(x_1,\ldots, x_n) for every x_1, \ldots, x_n, and s\ne 0. This is also referred to a ''th-degree'' or ''th-order'' homogeneous function. For example, a homogeneous polynomial of degree defines a homogeneous function of degree . The above definition extends to functions whose domain and codomain are vector spaces over a field : a function f : V \to W between two -vector spaces is ''homogeneous'' of degree k if for all nonzero s \in F and v \in V. This definition is often further generalized to functions whose domain is not , but a cone in , that is, a sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfoundations
Microfoundations are an effort to understand macroeconomic phenomena in terms of individual agents' economic behavior and interactions.Maarten Janssen (2008),Microfoundations, in ''The New Palgrave Dictionary of Economics'', 2nd ed. Research in microfoundations explores the link between Macroeconomics, macroeconomic and Microeconomics, microeconomic principles in order to explore the aggregate relationships in macroeconomic models. During recent decades, macroeconomists have attempted to combine microeconomic models of individual behaviour to derive the relationships between macroeconomic variables. Presently, many macroeconomic models, representing different theories, are Dynamic stochastic general equilibrium, derived by aggregating microeconomic models, allowing economists to test them with both macroeconomic and microeconomic data. However, microfoundations research is still heavily debated with management, strategy and organization scholars having varying views on the "micro-m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Economics
Mathematical economics is the application of Mathematics, mathematical methods to represent theories and analyze problems in economics. Often, these Applied mathematics#Economics, applied methods are beyond simple geometry, and may include differential and integral calculus, Recurrence relation, difference and differential equations, Matrix (mathematics), matrix algebra, mathematical programming, or other Computational economics, computational methods.TOC. Proponents of this approach claim that it allows the formulation of theoretical relationships with rigor, generality, and simplicity. Mathematics allows economists to form meaningful, testable propositions about wide-ranging and complex subjects which could less easily be expressed informally. Further, the language of mathematics allows economists to make specific, positiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overproduction
In economics, overproduction, oversupply, excess of supply, or glut refers to excess of supply over demand of products being offered to the market. This leads to lower prices and/or unsold goods along with the possibility of unemployment. The demand side equivalent is underconsumption; some consider supply and demand two sides to the same coin – excess supply is only relative to a given demand, and insufficient demand is only relative to a given supply – and thus consider overproduction and underconsumption equivalent. In lean thinking, overproduction of goods or goods in process is seen as one of the seven wastes (Japanese term: '' muda'') which do not add value to a product, and is considered "the most serious" of the seven.EKU OnlineThe Seven Wastes of Lean Manufacturing ''Eastern Kentucky University'', accessed 6 March 2023 Overproduction is often attributed to previous overinvestment – creation of excess productive capacity, which must then either lie idle ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortage
In economics, a shortage or excess demand is a situation in which the demand for a product or service exceeds its supply in a market. It is the opposite of an excess supply ( surplus). Definitions In a perfect market (one that matches a simple microeconomic model), an excess of demand will prompt sellers to increase prices until demand at that price matches the available supply, establishing market equilibrium. In economic terminology, a shortage occurs when for some reason (such as government intervention, or decisions by sellers not to raise prices) the price does not rise to reach equilibrium. In this circumstance, buyers want to purchase more at the market price than the quantity of the good or service that is available, and some non-price mechanism (such as "first come, first served" or a lottery) determines which buyers are served. So in a perfect market the only thing that can cause a shortage is price. In common use, the term "shortage" may refer to a situat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
