1.the branch of social science that deals with the production and distribution and consumption of goods and services and their management
1.(MeSH)The science of utilization, distribution, and consumption of services and materials.
EconomicsE`co*nom"ics (ē`kŏ*nŏm"ĭks), n. [Gr. ta` o'ikonomika`, equiv. to "h o'ikonomi`a. See Economic.]
1. The science of household affairs, or of domestic management.
2. Political economy; the science of the utilities or the useful application of wealth or material resources; the study of the production, distribution, and consumption of goods and services of a nation or region, and its effect on the wealth of a country. See Political economy, under Political. “In politics and economics.” V. Knox.
definição - Wikipedia
Capital (MeSH), Conditions, Economic (MeSH), Consumer Price Index (MeSH), Consumption (MeSH), Cost of Living (MeSH), Development, Economic (MeSH), Easterlin Hypothesis (MeSH), Economic Conditions (MeSH), Economic Development (MeSH), Economic Factors (MeSH), Economic Policies (MeSH), Economic Policy (MeSH), Economic Recession (MeSH), Economics, Home (MeSH), Factors, Economic (MeSH), Gross National Product (MeSH), Home Economics (MeSH), Household Consumption (MeSH), Macroeconomic Factors (MeSH), Microeconomic Factors (MeSH), Policies, Economic (MeSH), Policy, Economic (MeSH), Production (MeSH), Recession, Economic (MeSH), Remittances (MeSH), Utility Theory (MeSH)
Dental Economics • Economics, Dental • Economics, Home • Economics, Hospital • Economics, Medical • Economics, Nursing • Economics, Pharmaceutical • Health Care Economics and Organizations • Healthcare Economics and Organizations • Home Economics • Hospital Economics • Managerial-economics • Medical Economics • Nursing Economics • Pharmaceutical Economics • agricultural economics • annual statement of economics • applied economics • business economics • department of economics • economics department • economics profession • environmental economics • forestry economics • home economics • managerial economics • micro-economics • supply-side economics • transport economics
Academy of Economics in Bialystok • Academy of Economics in Krakow • Agent (economics) • American School (economics) • Applied Economics Research Centre • Applied economics • Appropriation (economics) • Athens University of Economics and Business • Autistic economics • Bachelor of Economics • Bad (economics) • Behavioral economics • Buddhist economics • Business and economics • Business economics • Butterfly Economics • Capital (economics) • Center for Popular Economics • Central University of Finance and Economics • Chicago school of economics • Classical economics • Co-operative economics • College of Home Economics • Common good (economics) • Community-based economics • Competition (economics) • Complexity economics • Computer Economics • Concise Encyclopedia of Economics • Consumer economics • Counter-economics • Cracow University of Economics • De La Salle University College of Business and Economics • Debt (economics) • Delhi School of Economics – MIB • Demand (economics) • Depression (economics) • Development economics • Distribution (economics) • Duty (economics) • Ecological economics • Economic imperialism (economics) • Economics (textbook) • Economics Education and Research Consortium • Economics Letters • Economics Research South Africa • Economics U$A • Economics and Human Biology • Economics and Statistics Administration • Economics and patents • Economics education • Economics of automobile usage • Economics of biodiversity • Economics of coffee • Economics of fascism • Economics of global warming • Economics of industrial organization • Economics of location • Economics of security • Economics of the United States • Economics of the arts and literature • Economics portal • Energy economics • Engineering economics • English historical school of economics • Entrepreneurial economics • Environmental economics • Essays in Positive Economics • Evolutionary economics • Family economics • Federal Ministry for Economics and Labour (Germany) • Feminist economics • Financial economics • Flypaper theory (economics) • Forensic economics • Foundation for the Economics of Sustainability • Gandhian economics • Gatton College of Business and Economics • Genetic algorithm in economics • Glenn Hubbard (economics) • Gokhale Institute of Politics and Economics • Happiness economics • Health Economics • Health economics • Heterodox economics • Higher Institute of Finances and Economics • Historical school of economics • Home Economics (disambiguation) • Humanistic economics • ISM University of Management and Economics • Imputation (economics) • Index of economics articles • Industrial Economics Institute • Institute of finance and economics of Mongolia • International Association for Energy Economics • Islamic economics in the world • Italian society of economics demography and statistics • Job (economics) • Journal of Accounting and Economics • Justice (economics) • Kazakhstan Institute of Management, Economics and Strategic Research • Keynesian economics • Kyiv School of Economics • Labour economics • Laissez-faire economics • Land (economics) • Land economics • Law and economics • Library of Economics and Liberty • List of German economics ministers • List of London School of Economics people • List of scholarly journals in economics • London School of Economics • Lund School of Economics and Management • MIT Department of Economics • Mainstream economics • Marxist school of economics • Max Planck Institute of Economics • Maximization (economics) • Medical economics • Micro-economics • Mineral economics • Minister of Economics and Labour (Germany) • Misery index (economics) • Monetary economics • Münster School of Business Administration and Economics • N.M College of commerce and Economics • NM College of Commerce and Economics • Narsee Monjee College of Commerce and Economics • Nationalist economics • Neoclassical economics • Neuro-economics • New Economics Foundation • New Keynesian economics • New institutional economics • Newtonian time in economics • Office of Manpower Economics • Osaka University of Economics • Overheating (economics) • Pakistan Institute of Development Economics • Participatory economics • Patriotic economics • Peterson Institute for International Economics • Post-Keynesian economics • Post-scarcity economics • Poznań University of Economics • Principles of Economics • Quarterly Journal of Austrian Economics • Quarterly Journal of Economics • Ramniranjan Anandilal Podar College of Commerce and Economics • Regulator (economics) • Regulatory economics • Relative value (economics) • Research Papers in Economics • Returns (economics) • Richard T. Gill (opera singer and economics professor) • Royal University of Law and Economics • Sabbath economics • School of Business, Economics and Law • School of Economics and Social Sciences • School of Economics, Business and Accounting of the University of São Paulo • Screening (economics) • Service (economics) • Shock therapy (economics) • Small Business Economics • Socialist economics • Southwestern University of Finance and Economics • Space Elevator Economics • Space Elevator economics • Space elevator Economics • Stagnation (economics) • Steady state economics • Stockholm School in economics • Stockholm School of Economics • Stockholm school (economics) • Sunspots (economics) • Superdollar (economics) • Supply (economics) • Supply-side economics • Surplus economics • The Economics and Ethics of Private Property • The Lighthouse in Economics • Transformative economics • Transport economics • University of Colombo Department of Economics • University of Economics in Bratislava • University of Economics in Katowice • Unsolved problems in economics • Urban economics • Value (economics) • Voodoo economics • Warwick Economics Summit • Welfare definition of economics • Welfare economics • Women and Economics • Wroclaw University of Economics • Wrocław University of Economics • Zhejiang University of Finance and Economics • İzmir University of Economics
Economics (n.) [MeSH]
science humaine (fr)[Classe]
science humaine (fr)[Classe]
science, scientific discipline[Hyper.]
History of economic thought
Methodology · Heterodox approaches
Experimental · National accounting
|Fields and subfields|
Behavioral · Cultural · Evolutionary
|Business and Economics Portal|
Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek οἰκονομία (oikonomia, "management of a household, administration") from οἶκος (oikos, "house") + νόμος (nomos, "custom" or "law"), hence "rules of the house(hold)". Political economy was the earlier name for the subject, but economists in the latter 19th century suggested 'economics' as a shorter term for 'economic science' that also avoided a narrow political-interest connotation and as similar in form to 'mathematics', 'ethics', and so forth.
A focus of the subject is how economic agents behave or interact and how economies work. Consistent with this, a primary textbook distinction is between microeconomics and macroeconomics. Microeconomics examines the behavior of basic elements in the economy, including individual agents (such as households and firms or as buyers and sellers) and markets, and their interactions. Macroeconomics analyzes the entire economy and issues affecting it, including unemployment, inflation, economic growth, and monetary and fiscal policy.
Other broad distinctions include those between positive economics (describing "what is") and normative economics (advocating "what ought to be"); between economic theory and applied economics; between rational and behavioral economics; and between mainstream economics (more "orthodox" and dealing with the "rationality-individualism-equilibrium nexus") and heterodox economics (more "radical" and dealing with the "institutions-history-social structure nexus").
Economic analysis may be applied throughout society, as in business, finance, health care, and government, but also to such diverse subjects as crime, education, the family, law, politics, religion, social institutions, war, and science. At the turn of the 21st century, the expanding domain of economics in the social sciences has been described as economic imperialism.
There are a variety of modern definitions of economics. Some of the differences may reflect evolving views of the subject or different views among economists. The philosopher Adam Smith (1776) defined what was then called political economy as "an inquiry into the nature and causes of the wealth of nations", in particular as:
J.-B. Say (1803), distinguishing the subject from its public-policy uses, defines it as the science of production, distribution, and consumption of wealth. On the satirical side, Thomas Carlyle (1849) coined 'the dismal science' as an epithet for classical economics, in this context, commonly linked to the pessimistic analysis of Malthus (1798). John Stuart Mill (1844) defines the subject in a social context as:
Robbins describes the definition as not classificatory in "pick[ing] out certain kinds of behaviour" but rather analytical in "focus[ing] attention on a particular aspect of behaviour, the form imposed by the influence of scarcity."
Some subsequent comments criticized the definition as overly broad in failing to limit its subject matter to analysis of markets. From the 1960s, however, such comments abated as the economic theory of maximizing behavior and rational-choice modeling expanded the domain of the subject to areas previously treated in other fields. There are other criticisms as well, such as in scarcity not accounting for the macroeconomics of high unemployment.
Gary Becker, a contributor to the expansion of economics into new areas, describes the approach he favors as "combin[ing the] assumptions of maximizing behavior, stable preferences, and market equilibrium, used relentlessly and unﬂinchingly." One commentary characterizes the remark as making economics an approach rather than a subject matter but with great specificity as to the "choice process and the type of social interaction that [such] analysis involves." The same source reviews a range of definitions included in principles of economics textbooks and concludes that the lack of agreement need not affect the subject-matter that the texts treat. Among economists more generally, it argues that a particular definition presented may reflect the direction toward which the author believes economics is evolving, or should evolve.
Microeconomics is the study of economics analysing individual players of a market and the structure of such markets. It deals with, as its irreducible base unit, private, public and domestic players. Microeconomics studies how these players interact with each other through individual markets (assuming that there is a scarcity of tradable units and government regulation. A market might deal with a product (such as apples, aluminium and mobile phones), or with services of a factor of production, (brick laying, book printing, food packaging). Microeconomics theory considers the aggregates (the sum of) of quantity demanded by buyers and quantity supplied by sellers, studying each possible price per unit (i.e. supply and demand). It studies the complex interaction between market players both through buying and selling. Theory holds that markets may reach equilibrium between "quantity demanded" and "quantity supplied" (supply and demand) over time.
Microeconomics also examines various market structures. Perfect competition describes a market structure such that no participants are large enough to have the market power to set the price of a homogeneous product. Another way of putting this is to say a perfectly competitive market exists when every participant is a "price taker", and no participant influences the price of the product it buys or sells. Imperfect competition refers to market structures where the conditions of perfect competition do not exist. Forms of imperfect competition include: monopoly (in which there is only one seller of a good), duopoly (in which there are only two sellers of a good), oligopoly (in which there are few sellers of a good), monopolistic competition (in which there are many sellers producing highly differentiated goods), monopsony (in which there is only one buyer of a good), and oligopsony (in which there are few buyers of a good). Unlike perfect competition, imperfect competition invariably means market power is unequally distributed. Firms under imperfect competition have the potential to be "price makers", which means that, by holding a disproportionately high share of market power, they can influence the prices of their products.
Microeconomics studies individual markets by simplifying the economic system by assuming that activity in the market being analysed does not affect other markets. This method of analysis is known as partial-equilibrium analysis (supply and demand). This method aggregates (the sum of all activity) in only one market. General-equilibrium theory studies various markets and their behaviour. It aggregates (the sum of all activity) across all markets. This method studies both changes in markets and their interactions leading towards equilibrium.
In microeconomics, production is the conversion of inputs into outputs. It is an economic process that uses inputs to create a commodity for exchange or direct use. Production is a flow and thus a rate of output per period of time. Distinctions include such production alternatives as for consumption (food, haircuts, etc.) vs. investment goods (new tractors, buildings, roads, etc.), public goods (national defense, small-pox vaccinations, etc.) or private goods (new computers, bananas, etc.), and "guns" vs. "butter".
Opportunity cost refers to the economic cost of production: the value of the next best opportunity foregone. Choices must be made between desirable yet mutually exclusive actions. It has been described as expressing "the basic relationship between scarcity and choice.". The opportunity cost of an activity is an element in ensuring that scarce resources are used efficiently, such that the cost is weighed against the value of that activity in deciding on more or less of it. Opportunity costs are not restricted to monetary or financial costs but could be measured by the real cost of output forgone, leisure, or anything else that provides the alternative benefit (utility).
Inputs used in the production process include such primary factors of production as labour services, capital (durable produced goods used in production, such as an existing factory), and land (including natural resources). Other inputs may include intermediate goods used in production of final goods, such as the steel in a new car.
Economic efficiency describes how well a system generates desired output with a given set of inputs and available technology. Efficiency is improved if more output is generated without changing inputs, or in other words, the amount of "waste" is reduced. A widely-accepted general standard is Pareto efficiency, which is reached when no further change can make someone better off without making someone else worse off.
The production-possibility frontier (PPF) is an expository figure for representing scarcity, cost, and efficiency. In the simplest case an economy can produce just two goods (say "guns" and "butter"). The PPF is a table or graph (as at the right) showing the different quantity combinations of the two goods producible with a given technology and total factor inputs, which limit feasible total output. Each point on the curve shows potential total output for the economy, which is the maximum feasible output of one good, given a feasible output quantity of the other good.
Scarcity is represented in the figure by people being willing but unable in the aggregate to consume beyond the PPF (such as at X) and by the negative slope of the curve. If production of one good increases along the curve, production of the other good decreases, an inverse relationship. This is because increasing output of one good requires transferring inputs to it from production of the other good, decreasing the latter. The slope of the curve at a point on it gives the trade-off between the two goods. It measures what an additional unit of one good costs in units forgone of the other good, an example of a real opportunity cost. Thus, if one more Gun costs 100 units of butter, the opportunity cost of one Gun is 100 Butter. Along the PPF, scarcity implies that choosing more of one good in the aggregate entails doing with less of the other good. Still, in a market economy, movement along the curve may indicate that the choice of the increased output is anticipated to be worth the cost to the agents.
By construction, each point on the curve shows productive efficiency in maximizing output for given total inputs. A point inside the curve (as at A), is feasible but represents production inefficiency (wasteful use of inputs), in that output of one or both goods could increase by moving in a northeast direction to a point on the curve. Examples cited of such inefficiency include high unemployment during a business-cycle recession or economic organization of a country that discourages full use of resources. Being on the curve might still not fully satisfy allocative efficiency (also called Pareto efficiency) if it does not produce a mix of goods that consumers prefer over other points.
Much applied economics in public policy is concerned with determining how the efficiency of an economy can be improved. Recognizing the reality of scarcity and then figuring out how to organize society for the most efficient use of resources has been described as the "essence of economics", where the subject "makes its unique contribution."
Specialization is considered key to economic efficiency based on theoretical and empirical considerations. Different individuals or nations may have different real opportunity costs of production, say from differences in stocks of human capital per worker or capital/labour ratios. According to theory, this may give a comparative advantage in production of goods that make more intensive use of the relatively more abundant, thus relatively cheaper, input. Even if one region has an absolute advantage as to the ratio of its outputs to inputs in every type of output, it may still specialize in the output in which it has a comparative advantage and thereby gain from trading with a region that lacks any absolute advantage but has a comparative advantage in producing something else.
It has been observed that a high volume of trade occurs among regions even with access to a similar technology and mix of factor inputs, including high-income countries. This has led to investigation of economies of scale and agglomeration to explain specialization in similar but differentiated product lines, to the overall benefit of respective trading parties or regions.
The general theory of specialization applies to trade among individuals, farms, manufacturers, service providers, and economies. Among each of these production systems, there may be a corresponding division of labour with different work groups specializing, or correspondingly different types of capital equipment and differentiated land uses.
An example that combines features above is a country that specializes in the production of high-tech knowledge products, as developed countries do, and trades with developing nations for goods produced in factories where labor is relatively cheap and plentiful, resulting in different in opportunity costs of production. More total output and utility thereby results from specializing in production and trading than if each country produced its own high-tech and low-tech products.
Theory and observation set out the conditions such that market prices of outputs and productive inputs select an allocation of factor inputs by comparative advantage, so that (relatively) low-cost inputs go to producing low-cost outputs. In the process, aggregate output may increase as a by-product or by design. Such specialization of production creates opportunities for gains from trade whereby resource owners benefit from trade in the sale of one type of output for other, more highly valued goods. A measure of gains from trade is the increased income levels that trade may facilitate.
Prices and quantities have been described as the most directly observable attributes of goods produced and exchanged in a market economy. The theory of supply and demand is an organizing principle for explaining how prices coordinate the amounts produced and consumed. In microeconomics, it applies to price and output determination for a market with perfect competition, which includes the condition of no buyers or sellers large enough to have price-setting power.
For a given market of a commodity, demand is the relation of the quantity that all buyers would be prepared to purchase at each unit price of the good. Demand is often represented by a table or a graph showing price and quantity demanded (as in the figure). Demand theory describes individual consumers as rationally choosing the most preferred quantity of each good, given income, prices, tastes, etc. A term for this is 'constrained utility maximization' (with income and wealth as the constraints on demand). Here, utility refers to the hypothesized relation of each individual consumer for ranking different commodity bundles as more or less preferred.
The law of demand states that, in general, price and quantity demanded in a given market are inversely related. That is, the higher the price of a product, the less of it people would be prepared to buy of it (other things unchanged). As the price of a commodity falls, consumers move toward it from relatively more expensive goods (the substitution effect). In addition, purchasing power from the price decline increases ability to buy (the income effect). Other factors can change demand; for example an increase in income will shift the demand curve for a normal good outward relative to the origin, as in the figure. All determinants are predominantly taken as constant factors of demand and supply.
Supply is the relation between the price of a good and the quantity available for sale at that price. It may be represented as a table or graph relating price and quantity supplied. Producers, for example business firms, are hypothesized to be profit-maximizers, meaning that they attempt to produce and supply the amount of goods that will bring them the highest profit. Supply is typically represented as a directly-proportional relation between price and quantity supplied (other things unchanged). That is, the higher the price at which the good can be sold, the more of it producers will supply, as in the figure. The higher price makes it profitable to increase production. Just as on the demand side, the position of the supply can shift, say from a change in the price of a productive input or a technical improvement. The "Law of Supply" states that, in general, a rise in price leads to an expansion in supply and a fall in price leads to a contraction in supply. Here as well, the determinants of supply, such as price of substitutes, cost of production, technology applied and various factors inputs of production are all taken to be constant for a specific time period of evaluation of supply.
Market equilibrium occurs where quantity supplied equals quantity demanded, the intersection of the supply and demand curves in the figure above. At a price below equilibrium, there is a shortage of quantity supplied compared to quantity demanded. This is posited to bid the price up. At a price above equilibrium, there is a surplus of quantity supplied compared to quantity demanded. This pushes the price down. The model of supply and demand predicts that for given supply and demand curves, price and quantity will stabilize at the price that makes quantity supplied equal to quantity demanded. Similarly, demand-and-supply theory predicts a new price-quantity combination from a shift in demand (as to the figure), or in supply.
For a given quantity of a consumer good, the point on the demand curve indicates the value, or marginal utility, to consumers for that unit. It measures what the consumer would be prepared to pay for that unit. The corresponding point on the supply curve measures marginal cost, the increase in total cost to the supplier for the corresponding unit of the good. The price in equilibrium is determined by supply and demand. In a perfectly competitive market, supply and demand equate marginal cost and marginal utility at equilibrium.
On the supply side of the market, some factors of production are described as (relatively) variable in the short run, which affects the cost of changing output levels. Their usage rates can be changed easily, such as electrical power, raw-material inputs, and over-time and temp work. Other inputs are relatively fixed, such as plant and equipment and key personnel. In the long run, all inputs may be adjusted by management. These distinctions translate to differences in the elasticity (responsiveness) of the supply curve in the short and long runs and corresponding differences in the price-quantity change from a shift on the supply or demand side of the market.
Marginalist theory, such as above, describes the consumers as attempting to reach most-preferred positions, subject to income and wealth constraints while producers attempt to maximize profits subject to their own constraints, including demand for goods produced, technology, and the price of inputs. For the consumer, that point comes where marginal utility of a good, net of price, reaches zero, leaving no net gain from further consumption increases. Analogously, the producer compares marginal revenue (identical to price for the perfect competitor) against the marginal cost of a good, with marginal profit the difference. At the point where marginal profit reaches zero, further increases in production of the good stop. For movement to market equilibrium and for changes in equilibrium, price and quantity also change "at the margin": more-or-less of something, rather than necessarily all-or-nothing.
Other applications of demand and supply include the distribution of income among the factors of production, including labour and capital, through factor markets. In a competitive labour market for example the quantity of labour employed and the price of labour (the wage rate) depends on the demand for labour (from employers for production) and supply of labour (from potential workers). Labour economics examines the interaction of workers and employers through such markets to explain patterns and changes of wages and other labour income, labour mobility, and (un)employment, productivity through human capital, and related public-policy issues.
Demand-and-supply analysis is used to explain the behavior of perfectly competitive markets, but as a standard of comparison it can be extended to any type of market. It can also be generalized to explain variables across the economy, for example, total output (estimated as real GDP) and the general price level, as studied in macroeconomics. Tracing the qualitative and quantitative effects of variables that change supply and demand, whether in the short or long run, is a standard exercise in applied economics. Economic theory may also specify conditions such that supply and demand through the market is an efficient mechanism for allocating resources.
People frequently do not trade directly on markets. Instead, on the supply side, they may work in and produce through firms. The most obvious kinds of firms are corporations, partnerships and trusts. According to Ronald Coase people begin to organise their production in firms when the costs of doing business becomes lower than doing it on the market. Firms combine labour and capital, and can achieve far greater economies of scale (when the average cost per unit declines as more units are produced) than individual market trading.
In perfectly-competitive markets studied in the theory of supply and demand, there are many producers, none of which significantly influence price. Industrial organization generalizes from that special case to study the strategic behavior of firms that do have significant control of price. It considers the structure of such markets and their interactions. Common market structures studied besides perfect competition include monopolistic competition, various forms of oligopoly, and monopoly.
Managerial economics applies microeconomic analysis to specific decisions in business firms or other management units. It draws heavily from quantitative methods such as operations research and programming and from statistical methods such as regression analysis in the absence of certainty and perfect knowledge. A unifying theme is the attempt to optimize business decisions, including unit-cost minimization and profit maximization, given the firm's objectives and constraints imposed by technology and market conditions.
Uncertainty in economics is an unknown prospect of gain or loss, whether quantifiable as risk or not. Without it, household behavior would be unaffected by uncertain employment and income prospects, financial and capital markets would reduce to exchange of a single instrument in each market period, and there would be no communications industry. Given its different forms, there are various ways of representing uncertainty and modelling economic agents' responses to it.
Game theory is a branch of applied mathematics that considers strategic interactions between agents, one kind of uncertainty. It provides a mathematical foundation of industrial organization, discussed above, to model different types of firm behavior, for example in an oligopolistic industry (few sellers), but equally applicable to wage negotiations, bargaining, contract design, and any situation where individual agents are few enough to have perceptible effects on each other. As a method heavily used in behavioral economics, it postulates that agents choose strategies to maximize their payoffs, given the strategies of other agents with at least partially conflicting interests. In this, it generalizes maximization approaches developed to analyze market actors such as in the supply and demand model and allows for incomplete information of actors. The field dates from the 1944 classic Theory of Games and Economic Behavior by John von Neumann and Oskar Morgenstern. It has significant applications seemingly outside of economics in such diverse subjects as formulation of nuclear strategies, ethics, political science, and evolutionary biology.
Risk aversion may stimulate activity that in well-functioning markets smooths out risk and communicates information about risk, as in markets for insurance, commodity futures contracts, and financial instruments. Financial economics or simply finance describes the allocation of financial resources. It also analyzes the pricing of financial instruments, the financial structure of companies, the efficiency and fragility of financial markets, financial crises, and related government policy or regulation.
Some market organizations may give rise to inefficiencies associated with uncertainty. Based on George Akerlof's "Market for Lemons" article, the paradigm example is of a dodgy second-hand car market. Customers without knowledge of whether a car is a "lemon" depress its price below what a quality second-hand car would be. Information asymmetry arises here, if the seller has more relevant information than the buyer but no incentive to disclose it. Related problems in insurance are adverse selection, such that those at most risk are most likely to insure (say reckless drivers), and moral hazard, such that insurance results in riskier behavior (say more reckless driving). Both problems may raise insurance costs and reduce efficiency in driving otherwise willing transactors from the market ("incomplete markets"). Moreover, attempting to reduce one problem, say adverse selection by mandating insurance, may add to another, say moral hazard. Information economics, which studies such problems, has relevance in subjects such as insurance, contract law, mechanism design, monetary economics, and health care. Applied subjects include market and legal remedies to spread or reduce risk, such as warranties, government-mandated partial insurance, restructuring or bankruptcy law, inspection, and regulation for quality and information disclosure.
The term "market failure" encompasses several problems which may undermine standard economic assumptions. Although economists categorise market failures differently, the following categories emerge in the main texts.
Natural monopoly, or the overlapping concepts of "practical" and "technical" monopoly, is an extreme case of failure of competition as a restraint on producers. The problem is described as one where the more of a product is made, the lower the unit costs are. This means it only makes economic sense to have one producer.
Public goods are goods which are undersupplied in a typical market. The defining features are that people can consume public goods without having to pay for them and that more than one person can consume the good at the same time.
Externalities occur where there are significant social costs or benefits from production or consumption that are not reflected in market prices. For example, air pollution may generate a negative externality, and education may generate a positive externality (less crime, etc.). Governments often tax and otherwise restrict the sale of goods that have negative externalities and subsidize or otherwise promote the purchase of goods that have positive externalities in an effort to correct the price distortions caused by these externalities. Elementary demand-and-supply theory predicts equilibrium but not the speed of adjustment for changes of equilibrium due to a shift in demand or supply.
In many areas, some form of price stickiness is postulated to account for quantities, rather than prices, adjusting in the short run to changes on the demand side or the supply side. This includes standard analysis of the business cycle in macroeconomics. Analysis often revolves around causes of such price stickiness and their implications for reaching a hypothesized long-run equilibrium. Examples of such price stickiness in particular markets include wage rates in labour markets and posted prices in markets deviating from perfect competition.
Macroeconomic instability, addressed below, is a prime source of market failure, whereby a general loss of business confidence or external shock can grind production and distribution to a halt, undermining ordinary markets that are otherwise sound.
Some specialised fields of economics deal in market failure more than others. The economics of the public sector is one example, since where markets fail, some kind of regulatory or government programme is the remedy. Much environmental economics concerns externalities or "public bads".
Public finance is the field of economics that deals with budgeting the revenues and expenditures of a public sector entity, usually government. The subject addresses such matters as tax incidence (who really pays a particular tax), cost-benefit analysis of government programs, effects on economic efficiency and income distribution of different kinds of spending and taxes, and fiscal politics. The latter, an aspect of public choice theory, models public-sector behavior analogously to microeconomics, involving interactions of self-interested voters, politicians, and bureaucrats.
Welfare economics is a normative branch of economics that uses microeconomic techniques to simultaneously determine the allocative efficiency within an economy and the income distribution associated with it. It attempts to measure social welfare by examining the economic activities of the individuals that comprise society.
Macroeconomics examines the economy as a whole to explain broad aggregates and their interactions "top down", that is, using a simplified form of general-equilibrium theory. Such aggregates include national income and output, the unemployment rate, and price inflation and subaggregates like total consumption and investment spending and their components. It also studies effects of monetary policy and fiscal policy.
Since at least the 1960s, macroeconomics has been characterized by further integration as to micro-based modeling of sectors, including rationality of players, efficient use of market information, and imperfect competition. This has addressed a long-standing concern about inconsistent developments of the same subject.
Growth economics studies factors that explain economic growth – the increase in output per capita of a country over a long period of time. The same factors are used to explain differences in the level of output per capita between countries, in particular why some countries grow faster than others, and whether countries converge at the same rates of growth.
Much-studied factors include the rate of investment, population growth, and technological change. These are represented in theoretical and empirical forms (as in the neoclassical and endogenous growth models) and in growth accounting.
The economics of a depression were the spur for the creation of "macroeconomics" as a separate discipline field of study. During the Great Depression of the 1930s, John Maynard Keynes authored a book entitled The General Theory of Employment, Interest and Money outlining the key theories of Keynesian economics. Keynes contended that aggregate demand for goods might be insufficient during economic downturns, leading to unnecessarily high unemployment and losses of potential output.
He therefore advocated active policy responses by the public sector, including monetary policy actions by the central bank and fiscal policy actions by the government to stabilize output over the business cycle Thus, a central conclusion of Keynesian economics is that, in some situations, no strong automatic mechanism moves output and employment towards full employment levels. John Hicks' IS/LM model has been the most influential interpretation of The General Theory.
Over the years, the understanding of the business cycle has branched into various schools, related to or opposed to Keynesianism. The neoclassical synthesis refers to the reconciliation of Keynesian economics with neoclassical economics, stating that Keynesianism is correct in the short run, with the economy following neoclassical theory in the long run.
The New classical school critiques the Keynesian view of the business cycle. It includes Friedman's permanent income hypothesis view on consumption, the "rational expectations revolution" spearheaded by Robert Lucas, and real business cycle theory.
In contrast, the New Keynesian school retains the rational expectations assumption, however it assumes a variety of market failures. In particular, New Keynesians assume prices and wages are "sticky", which means they do not adjust instantaneously to changes in economic conditions.
Thus, the new classicals assume that prices and wages adjust automatically to attain full employment, whereas the new Keynesians see full employment as being automatically achieved only in the long run, and hence government and central-bank policies are needed because the "long run" may be very long.
Money is a means of final payment for goods in most price system economies and the unit of account in which prices are typically stated. A very apt statement by Professor Walker, a well-known economist is that, " Money is what money does...". Money has a general acceptability, a relative consistency in value, divisibility, durability, portability, elastic in supply and survives with mass public confidence. It includes currency held by the nonbank public and checkable deposits. It has been described as a social convention, like language, useful to one largely because it is useful to others.
As a medium of exchange, money facilitates trade. It is essentially a measure of value and more importantly, a store of value being a basis for credit creation. Its economic function can be contrasted with barter (non-monetary exchange). Given a diverse array of produced goods and specialized producers, barter may entail a hard-to-locate double coincidence of wants as to what is exchanged, say apples and a book. Money can reduce the transaction cost of exchange because of its ready acceptability. Then it is less costly for the seller to accept money in exchange, rather than what the buyer produces.
At the level of an economy, theory and evidence are consistent with a positive relationship running from the total money supply to the nominal value of total output and to the general price level. For this reason, management of the money supply is a key aspect of monetary policy.
National accounting is a method for summarizing aggregate economic activity of a nation. The national accounts are double-entry accounting systems that provide detailed underlying measures of such information. These include the national income and product accounts (NIPA), which provide estimates for the money value of output and income per year or quarter.
NIPA allows for tracking the performance of an economy and its components through business cycles or over longer periods. Price data may permit distinguishing nominal from real amounts, that is, correcting money totals for price changes over time. The national accounts also include measurement of the capital stock, wealth of a nation, and international capital flows.
International trade studies determinants of goods-and-services flows across international boundaries. It also concerns the size and distribution of gains from trade. Policy applications include estimating the effects of changing tariff rates and trade quotas. International finance is a macroeconomic field which examines the flow of capital across international borders, and the effects of these movements on exchange rates. Increased trade in goods, services and capital between countries is a major effect of contemporary globalization.
The distinct field of development economics examines economic aspects of the development process in relatively low-income countries focusing on structural change, poverty, and economic growth. Approaches in development economics frequently incorporate social and political factors.
Economic systems is the branch of economics that studies the methods and institutions by which societies determine the ownership, direction, and allocation of economic resources. An economic system of a society is the unit of analysis.
Among contemporary systems at different ends of the organizational spectrum are socialist systems and capitalist systems, in which most production occurs in respectively state-run and private enterprises. In between are mixed economies. A common element is the interaction of economic and political influences, broadly described as political economy. Comparative economic systems studies the relative performance and behavior of different economies or systems.
Contemporary economics uses mathematics. Economists draw on the tools of calculus, linear algebra, statistics, game theory, and computer science. Professional economists are expected to be familiar with these tools, while a minority specialize in econometrics and mathematical methods.
Mainstream economic theory relies upon a priori quantitative economic models, which employ a variety of concepts. Theory typically proceeds with an assumption of ceteris paribus, which means holding constant explanatory variables other than the one under consideration. When creating theories, the objective is to find ones which are at least as simple in information requirements, more precise in predictions, and more fruitful in generating additional research than prior theories.
In microeconomics, principal concepts include supply and demand, marginalism, rational choice theory, opportunity cost, budget constraints, utility, and the theory of the firm. Early macroeconomic models focused on modeling the relationships between aggregate variables, but as the relationships appeared to change over time macroeconomists were pressured to base their models in microfoundations.
The aforementioned microeconomic concepts play a major part in macroeconomic models – for instance, in monetary theory, the quantity theory of money predicts that increases in the money supply increase inflation, and inflation is assumed to be influenced by rational expectations. In development economics, slower growth in developed nations has been sometimes predicted because of the declining marginal returns of investment and capital, and this has been observed in the Four Asian Tigers. Sometimes an economic hypothesis is only qualitative, not quantitative.
Expositions of economic reasoning often use two-dimensional graphs to illustrate theoretical relationships. At a higher level of generality, Paul Samuelson's treatise Foundations of Economic Analysis (1947) used mathematical methods to represent the theory, particularly as to maximizing behavioral relations of agents reaching equilibrium. The book focused on examining the class of statements called operationally meaningful theorems in economics, which are theorems that can conceivably be refuted by empirical data.
Economic theories are frequently tested empirically, largely through the use of econometrics using economic data. The controlled experiments common to the physical sciences are difficult and uncommon in economics, and instead broad data is observationally studied; this type of testing is typically regarded as less rigorous than controlled experimentation, and the conclusions typically more tentative. However, the field of experimental economics is growing, and increasing use is being made of natural experiments.
Statistical methods such as regression analysis are common. Practitioners use such methods to estimate the size, economic significance, and statistical significance ("signal strength") of the hypothesized relation(s) and to adjust for noise from other variables. By such means, a hypothesis may gain acceptance, although in a probabilistic, rather than certain, sense. Acceptance is dependent upon the falsifiable hypothesis surviving tests. Use of commonly accepted methods need not produce a final conclusion or even a consensus on a particular question, given different tests, data sets, and prior beliefs.
Criticism based on professional standards and non-replicability of results serve as further checks against bias, errors, and over-generalization, although much economic research has been accused of being non-replicable, and prestigious journals have been accused of not facilitating replication through the provision of the code and data. Like theories, uses of test statistics are themselves open to critical analysis, although critical commentary on papers in economics in prestigious journals such as the American Economic Review has declined precipitously in the past 40 years. This has been attributed to journals' incentives to maximize citations in order to rank higher on the Social Science Citation Index (SSCI).
In applied economics, input-output models employing linear programming methods are quite common. Large amounts of data are run through computer programs to analyze the impact of certain policies; IMPLAN is one well-known example.
Experimental economics has promoted the use of scientifically controlled experiments. This has reduced long-noted distinction of economics from natural sciences allowed direct tests of what were previously taken as axioms. In some cases these have found that the axioms are not entirely correct; for example, the ultimatum game has revealed that people reject unequal offers.
In behavioral economics, psychologist Daniel Kahneman won the Nobel Prize in economics in 2002 for his and Amos Tversky's empirical discovery of several cognitive biases and heuristics. Similar empirical testing occurs in neuroeconomics. Another example is the assumption of narrowly selfish preferences versus a model that tests for selfish, altruistic, and cooperative preferences. These techniques have led some to argue that economics is a "genuine science."
The professionalization of economics, reflected in the growth of graduate programs on the subject, has been described as "the main change in economics since around 1900". Most major universities and many colleges have a major, school, or department in which academic degrees are awarded in the subject, whether in the liberal arts, business, or for professional study; see Master of Economics.
The Nobel Memorial Prize in Economic Sciences (commonly known as the Nobel Prize in Economics) is a prize awarded to economists each year for outstanding intellectual contributions in the field. In the private sector, professional economists are employed as consultants and in industry, including banking and finance. Economists also work for various government departments and agencies, for example, the national Treasury, Central Bank or Bureau of Statistics.
Economics is one social science among several and has fields bordering on other areas, including economic geography, economic history, public choice, energy economics, cultural economics, and institutional economics.
Law and economics, or economic analysis of law, is an approach to legal theory that applies methods of economics to law. It includes the use of economic concepts to explain the effects of legal rules, to assess which legal rules are economically efficient, and to predict what the legal rules will be. A seminal article by Ronald Coase published in 1961 suggested that well-defined property rights could overcome the problems of externalities.
Political economy is the interdisciplinary study that combines economics, law, and political science in explaining how political institutions, the political environment, and the economic system (capitalist, socialist, mixed) influence each other. It studies questions such as how monopoly, rent-seeking behavior, and externalities should impact government policy. Historians have employed political economy to explore the ways in the past that persons and groups with common economic interests have used politics to effect changes beneficial to their interests.
Energy economics is a broad scientific subject area which includes topics related to energy supply and energy demand. Georgescu-Roegen reintroduced the concept of entropy in relation to economics and energy from thermodynamics, as distinguished from what he viewed as the mechanistic foundation of neoclassical economics drawn from Newtonian physics. His work contributed significantly to thermoeconomics and to ecological economics. He also did foundational work which later developed into evolutionary economics.
The sociological subfield of economic sociology arose, primarily through the work of Émile Durkheim, Max Weber and Georg Simmel, as an approach to analysing the effects of economic phenomena in relation to the overarching social paradigm (i.e. modernity). Classic works include Max Weber's The Protestant Ethic and the Spirit of Capitalism (1905) and Georg Simmel's The Philosophy of Money (1900). More recently, the works of Mark Granovetter, Peter Hedstrom and Richard Swedberg have been influential in this field.
Economic writings date from earlier Mesopotamian, Greek, Roman, Indian subcontinent, Chinese, Persian, and Arab civilizations. Notable writers from antiquity through to the 14th century include Aristotle, Xenophon, Chanakya (also known as Kautilya), Qin Shi Huang, Thomas Aquinas, and Ibn Khaldun. The works of Aristotle had a profound influence on Aquinas, who in turn influenced the late scholastics of the 14th to 17th centuries. Joseph Schumpeter described the latter as "coming nearer than any other group to being the 'founders' of scientific economics" as to monetary, interest, and value theory within a natural-law perspective.[not in citation given]
Two groups, later called 'mercantilists' and 'physiocrats', more directly influenced the subsequent development of the subject. Both groups were associated with the rise of economic nationalism and modern capitalism in Europe. Mercantilism was an economic doctrine that flourished from the 16th to 18th century in a prolific pamphlet literature, whether of merchants or statesmen. It held that a nation's wealth depended on its accumulation of gold and silver. Nations without access to mines could obtain gold and silver from trade only by selling goods abroad and restricting imports other than of gold and silver. The doctrine called for importing cheap raw materials to be used in manufacturing goods, which could be exported, and for state regulation to impose protective tariffs on foreign manufactured goods and prohibit manufacturing in the colonies.
Physiocrats, a group of 18th century French thinkers and writers, developed the idea of the economy as a circular flow of income and output. Physiocrats believed that only agricultural production generated a clear surplus over cost, so that agriculture was the basis of all wealth. Thus, they opposed the mercantilist policy of promoting manufacturing and trade at the expense of agriculture, including import tariffs. Physiocrats advocated replacing administratively costly tax collections with a single tax on income of land owners. In reaction against copious mercantilist trade regulations, the physiocrats advocated a policy of laissez-faire, which called for minimal government intervention in the economy.
Modern economic analysis is customarily said to have begun with Adam Smith (1723–1790). Smith was harshly critical of the mercantilists but described the physiocratic system "with all its imperfections" as "perhaps the purest approximation to the truth that has yet been published" on the subject.
Publication of Adam Smith's The Wealth of Nations in 1776, has been described as "the effective birth of economics as a separate discipline." The book identified land, labor, and capital as the three factors of production and the major contributors to a nation's wealth, as distinct from the Physiocratic idea that only agriculture was productive.
Smith discusses potential benefits of specialization by division of labour, including increased labor productivity and gains from trade, whether between town and country or across countries. His "theorem" that "the division of labor is limited by the extent of the market" has been described as the "core of a theory of the functions of firm and industry" and a "fundamental principle of economic organization." To Smith has also been ascribed "the most important substantive proposition in all of economics" and foundation of resource-allocation theory – that, under competition, resource owners (of labor, land, and capital) seek their most profitable uses, resulting in an equal rate of return for all uses in equilibrium (adjusted for apparent differences arising from such factors as training and unemployment).
In an argument that includes "one of the most famous passages in all economics," Smith represents every individual as trying to employ any capital they might command for their own advantage, not that of the society, and for the sake of profit, which is necessary at some level for employing capital in domestic industry, and positively related to the value of produce. In this:
Economists have linked Smith's invisible-hand concept to his concern for the common man and woman through economic growth and development, enabling higher levels of consumption, which Smith describes as "the sole end and purpose of all production." He embeds the 'invisible hand' in a framework that includes limiting restrictions on competition and foreign trade by government and industry in the same chapter and elsewhere regulation of banking and the interest rate, provision of a "natural system of liberty" — national defence, an egalitarian justice and legal system, and certain institutions and public works with general benefits to the whole society that might otherwise be unprofitable to produce, such as education and roads, canals, and the like. An influential introductory textbook includes parallel discussion and this assessment: "Above all, it is Adam Smith's vision of a self-regulating invisible hand that is his enduring contribution to modern economics."
The Rev. Thomas Robert Malthus (1798) used the idea of diminishing returns to explain low living standards. Human population, he argued, tended to increase geometrically, outstripping the production of food, which increased arithmetically. The force of a rapidly growing population against a limited amount of land meant diminishing returns to labor. The result, he claimed, was chronically low wages, which prevented the standard of living for most of the population from rising above the subsistence level.
Malthus also questioned the automatic tendency of a market economy to produce full employment. He blamed unemployment upon the economy's tendency to limit its spending by saving too much, a theme that lay forgotten until John Maynard Keynes revived it in the 1930s.
While Adam Smith emphasized the production of income, David Ricardo (1817) focused on the distribution of income among landowners, workers, and capitalists. Ricardo saw an inherent conflict between landowners on the one hand and labor and capital on the other. He posited that the growth of population and capital, pressing against a fixed supply of land, pushes up rents and holds down wages and profits. Ricardo was the first to state and prove the principle of comparative advantage, according to which each country should specialize in producing and exporting goods in that it has a lower relative cost of production, rather relying only on its own production. It has been termed a "fundamental analytical explanation" for gains from trade.
Coming at the end of the Classical tradition, John Stuart Mill (1848) parted company with the earlier classical economists on the inevitability of the distribution of income produced by the market system. Mill pointed to a distinct difference between the market's two roles: allocation of resources and distribution of income. The market might be efficient in allocating resources but not in distributing income, he wrote, making it necessary for society to intervene.
Value theory was important in classical theory. Smith wrote that the "real price of every thing ... is the toil and trouble of acquiring it" as influenced by its scarcity. Smith maintained that, with rent and profit, other costs besides wages also enter the price of a commodity. Other classical economists presented variations on Smith, termed the 'labour theory of value'. Classical economics focused on the tendency of markets to move to long-run equilibrium.
Marxist (later, Marxian) economics descends from classical economics. It derives from the work of Karl Marx. The first volume of Marx's major work, Das Kapital, was published in German in 1867. In it, Marx focused on the labour theory of value and what he considered to be the exploitation of labour by capital. The labour theory of value held that the value of an exchanged commodity was determined by the labor that went into its production.
A body of theory later termed 'neoclassical economics' or 'marginalism' formed from about 1870 to 1910. The term 'economics' was popularized by such neoclassical economists as Alfred Marshall as a concise synonym for 'economic science' and a substitute for the earlier 'political economy'. This corresponded to the influence on the subject of mathematical methods used in the natural sciences.
Neoclassical economics systematized supply and demand as joint determinants of price and quantity in market equilibrium, affecting both the allocation of output and the distribution of income. It dispensed with the labour theory of value inherited from classical economics in favor of a marginal utility theory of value on the demand side and a more general theory of costs on the supply side. In the 20th century, neoclassical theorists moved away from an earlier notion suggesting that total utility for a society could be measured in favor of ordinal utility, which hypothesizes merely behavior-based relations across persons.
In microeconomics, neoclassical economics represents incentives and costs as playing a pervasive role in shaping decision making. An immediate example of this is the consumer theory of individual demand, which isolates how prices (as costs) and income affect quantity demanded. In macroeconomics it is reflected in an early and lasting neoclassical synthesis with Keynesian macroeconomics.
Neoclassical economics is occasionally referred as orthodox economics whether by its critics or sympathizers. Modern mainstream economics builds on neoclassical economics but with many refinements that either supplement or generalize earlier analysis, such as econometrics, game theory, analysis of market failure and imperfect competition, and the neoclassical model of economic growth for analyzing long-run variables affecting national income.
Keynesian economics derives from John Maynard Keynes, in particular his book The General Theory of Employment, Interest and Money (1936), which ushered in contemporary macroeconomics as a distinct field. The book focused on determinants of national income in the short run when prices are relatively inflexible. Keynes attempted to explain in broad theoretical detail why high labour-market unemployment might not be self-correcting due to low "effective demand" and why even price flexibility and monetary policy might be unavailing. Such terms as "revolutionary" have been applied to the book in its impact on economic analysis.
Keynesian economics has two successors. Post-Keynesian economics also concentrates on macroeconomic rigidities and adjustment processes. Research on micro foundations for their models is represented as based on real-life practices rather than simple optimizing models. It is generally associated with the University of Cambridge and the work of Joan Robinson.
New-Keynesian economics is also associated with developments in the Keynesian fashion. Within this group researchers tend to share with other economists the emphasis on models employing micro foundations and optimizing behavior but with a narrower focus on standard Keynesian themes such as price and wage rigidity. These are usually made to be endogenous features of the models, rather than simply assumed as in older Keynesian-style ones.
The Chicago School of economics is best known for its free market advocacy and monetarist ideas. According to Milton Friedman and monetarists, market economies are inherently stable if the money supply does not greatly expand or contract. Ben Bernanke, current Chairman of the Federal Reserve, is among the economists today generally accepting Friedman's analysis of the causes of the Great Depression.
Milton Friedman effectively took many of the basic principles set forth by Adam Smith and the classical economists and modernized them. One example of this is his article in the September 1970 issue of The New York Times Magazine, where he claims that the social responsibility of business should be "to use its resources and engage in activities designed to increase its profits...(through) open and free competition without deception or fraud." 
Other well-known schools or trends of thought referring to a particular style of economics practiced at and disseminated from well-defined groups of academicians that have become known worldwide, include the Austrian School, the Freiburg School, the School of Lausanne, post-Keynesian economics and the Stockholm school. Contemporary mainstream economics is sometimes separated into the Saltwater approach of those universities along the Eastern and Western coasts of the US, and the Freshwater, or Chicago-school approach.
Within macroeconomics there is, in general order of their appearance in the literature; classical economics, Keynesian economics, the neoclassical synthesis, post-Keynesian economics, monetarism, new classical economics, and supply-side economics. Alternative developments include ecological economics, constitutional economics, institutional economics, evolutionary economics, dependency theory, structuralist economics, world systems theory, econophysics, feminist economics and biophysical economics.
"The dismal science" is a derogatory alternative name for economics devised by the Victorian historian Thomas Carlyle in the 19th century. It is often stated that Carlyle gave economics the nickname "the dismal science" as a response to the late 18th century writings of The Reverend Thomas Robert Malthus, who grimly predicted that starvation would result, as projected population growth exceeded the rate of increase in the food supply. However, the actual phrase was coined by Carlyle in the context of a debate with John Stuart Mill on slavery, in which Carlyle argued for slavery, while Mill opposed it.
Some economists, like John Stuart Mill or Léon Walras, have maintained that the production of wealth should not be tied to its distribution. The former is in the field of "applied economics" while the latter belongs to "social economics" and is largely a matter of power and politics.
In The Wealth of Nations, Adam Smith addressed many issues that are currently also the subject of debate and dispute. Smith repeatedly attacks groups of politically aligned individuals who attempt to use their collective influence to manipulate a government into doing their bidding. In Smith's day, these were referred to as factions, but are now more commonly called special interests, a term which can comprise international bankers, corporate conglomerations, outright oligopolies, monopolies, trade unions and other groups.
Economics per se, as a social science, is independent of the political acts of any government or other decision-making organization, however, many policymakers or individuals holding highly ranked positions that can influence other people's lives are known for arbitrarily using a plethora of economic concepts and rhetoric as vehicles to legitimize agendas and value systems, and do not limit their remarks to matters relevant to their responsibilities. The close relation of economic theory and practice with politics is a focus of contention that may shade or distort the most unpretentious original tenets of economics, and is often confused with specific social agendas and value systems. Notwithstanding, economics legitimately has a role in informing government policy. It is, indeed, in some ways an outgrowth of the older field of political economy. Some academic economic journals are currently focusing increased efforts on gauging the consensus of economists regarding certain policy issues in hopes of effecting a more informed political environment. Currently, there exists a low approval rate from professional economists regarding many public policies. Policy issues featured in a recent survey of AEA economists include trade restrictions, social insurance for those put out of work by international competition, genetically modified foods, curbside recycling, health insurance (several questions), medical malpractice, barriers to entering the medical profession, organ donations, unhealthy foods, mortgage deductions, taxing internet sales, Wal-Mart, casinos, ethanol subsidies, and inflation targeting.
Issues like central bank independence, central bank policies and rhetoric in central bank governors discourse or the premises of macroeconomic policies (monetary and fiscal policy) of the state, are focus of contention and criticism.
Deirdre McCloskey has argued that many empirical economic studies are poorly reported, and while her critique has been well-received, she and Stephen Ziliak argue that practice has not improved. This latter contention is controversial.
A 2002 International Monetary Fund study looked at "consensus forecasts" (the forecasts of large groups of economists) that were made in advance of 60 different national recessions in the ’90s: in 97% of the cases the economists did not predict the contraction a year in advance. On those rare occasions when economists did successfully predict recessions, they significantly underestimated their severity.
Economics has been subject to criticism that it relies on unrealistic, unverifiable, or highly simplified assumptions, in some cases because these assumptions simplify the proofs of desired conclusions. Examples of such assumptions include perfect information, profit maximization and rational choices.  The field of information economics includes both mathematical-economical research and also behavioral economics, akin to studies in behavioral psychology.
Nevertheless, prominent mainstream economists such as Keynes and Joskow have observed that much of economics is conceptual rather than quantitative, and difficult to model and formalize quantitatively. In a discussion on oligopoly research, Paul Joskow pointed out in 1975 that in practice, serious students of actual economies tended to use "informal models" based upon qualitative factors specific to particular industries. Joskow had a strong feeling that the important work in oligopoly was done through informal observations while formal models were "trotted out ex post". He argued that formal models were largely not important in the empirical work, either, and that the fundamental factor behind the theory of the firm, behavior, was neglected.
In recent years, feminist critiques of neoclassical economic models gained prominence, leading to the formation of feminist economics. Contrary to common conceptions of economics as a positive and objective science, feminist economists call attention to the social construction of economics and highlight the ways in which its models and methods reflect masculine preferences. Primary criticisms focus on failures to account for: the selfish nature of actors (homo economicus); exogenous tastes; the impossibility of utility comparisons; the exclusion of unpaid work; and the exclusion of class and gender considerations. Feminist economics developed to address these concerns, and the field now includes critical examinations of many areas of economics including paid and unpaid work, economic epistemology and history, globalization, household economics and the care economy. Feminists such as Marilyn Waring also argue that the discipline of economics ignores women's unpaid work and the value of nature.
Philip Mirowski observes that
The imperatives of the orthodox research programme [of economic science] leave little room for maneuver and less room for originality. ... These mandates ... Appropriate as many mathematical techniques and metaphorical expressions from contemporary respectable science, primarily physics as possible. ... Preserve to the maximum extent possible the attendant nineteenth-century overtones of “natural order” ... Deny strenuously that neoclassical theory slavishly imitates physics. ... Above all, prevent all rival research programmes from encroaching ... by ridiculing all external attempts to appropriate twentieth century physics models. ... All theorizing is [in this way] held hostage to nineteenth-century concepts of energy. 
In a series of peer-reviewed journal and conference papers and books published over a period of several decades, John McMurtry has provided extensive criticism of what he terms the "unexamined assumptions and implications [of economics], and their consequent cost to people’s lives." For example, he writes
This is why we might conclude that economics ceased to be a science or an investigation once it presupposed an engineering physics model as its methodological given. It became instead the defining software of a machinal system with no place for life in its money-sequence operations. Like the received dogma of another epoch, its formulations decoupled from reality in a scholastic formalism, its priesthood would not acknowledge the right of any but trained believers to speak on issues designated by the subject, and its iron laws subsumed all that lived as material ready to be made productive by transformation into the system’s service. ... Yet it would be a very great mistake to simply reject economics as a resource of analysis. It provides an articulated lexicon of exact referents, operations and principles of the global market mechanism which it presupposes as the natural order. And its resources are invaluable in coming to understand the system of rule which the global market now implements across the world in its restructuring operations. One has to expose and understand the principles the doctrine assumes in order to examine and unmask their implications for life-organization. One has to follow the assumptions its theoreticians take as given to see the trail of consequences for reality which obedience to this unseen metaphysic unleashes on the world. One has to connect across the logical lattice of the covert value system the defining axioms and co-ordinates it bears to see what it means for the planetary life-web as an integrated whole. One has, in short, to do what the economist avoids as the explosion of his own identity – open up its value structure to examination. This is what the study which follows [in this book] does ... 
Nassim Nicholas Taleb and Michael Perelman are two additional scholars who criticized conventional or mainstream economics. Taleb opposes most economic theorizing, which in his view suffers acutely from the problem of overuse of Plato's Theory of Forms, and calls for cancellation of the Nobel Memorial Prize in Economics, saying that the damage from economic theories can be devastating. Michael Perelman provides extensive criticism of economics and its assumptions in all his books (and especially his books published from 2000 to date), papers and interviews. For example, he says:
The disconnect between what purports to be objective analysis [by classical political economists] and the underlying power relationships fascinates me. Like Moliere's bourgeois gentlemen, who was unaware that he was speaking prose, economists have developed a culture in which they communicate without any recognition of how much they have internalized the distorted perspective of a capitalist system. What is more surprising is how thoroughly the economists were able to propagate their flawed worldview throughout much of society. The economic worldview loses sight of essential elements of the world economists analyze. Once their simplistic world of economics spins out of control, economists' instinct is to explain away their deficiencies rather than finally coming to grips with the real world. In that sense, I feel that a critical study of economists and their economics becomes useful as a means of self-defense against the tyranny of markets. ... In their published books, the political economists at the time ignored the injustices associated with the enforcement of the feudal game laws, as well as the enormous economic damage done by the hunters. Instead, they described the economy as the result of voluntary transactions between willing buyers and sellers. Away from the public eye, these same economists applauded the displacement of rural masses, which was providing new bodies for the emerging proletariat. In this sense, capitalism was invented as I described in [the book] The Invention of Capitalism. Capitalism was invented in another sense. The early economists described the emergence of capitalism as a voluntary system that benefited everybody. This falsification of history, which was central to their analysis, was a very creative invention ... In [the book] The Invisible Handcuffs, I tried to show how economists tried to frame capitalism as a system of voluntary transactions, as I mentioned [above]. One can understand how the economists could have gotten away with this evasion of reality in a world when literacy was limited and communications [was] expensive. In a modern world, to be able to get away with such nonsense is an audacious act of genius. Economic theory also abstracts from virtually anything having to do with time.
|Wikipedia books are collections of articles that can be downloaded or ordered in print.|
|Look up economics in Wiktionary, the free dictionary.|
|Find more about Economics on Wikipedia's sister projects:|
|Definitions and translations from Wiktionary
|Images and media from Commons
|Learning resources from Wikiversity
|News stories from Wikinews
|Quotations from Wikiquote
|Source texts from Wikisource
|Textbooks from Wikibooks
|Wikiversity has learning materials about School:Economics|
Conteùdo de sensagent