Microeconomics (from Greek prefix mikro- meaning "small" + economics) is a branch of economics that studies the behaviour of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms.
One goal of microeconomics is to analyze the market mechanisms that establish relative prices among goods and services and allocate limited resources among alternative uses. Microeconomics shows conditions under which free markets lead to desirable allocations. It also analyzes market failure, where markets fail to produce efficient results.
Microeconomics stands in contrast to macroeconomics, which involves "the sum total of economic activity, dealing with the issues of growth, inflation, and unemployment and with national policies relating to these issues". Microeconomics also deals with the effects of economic policies (such as changing taxation levels) on microeconomic behavior and thus on the aforementioned aspects of the economy. Particularly in the wake of the Lucas critique, much of modern macroeconomic theories has been built upon microfoundations—i.e. based upon basic assumptions about micro-level behavior.
Microeconomic theory typically begins with the study of a single rational and utility maximizing individual. To economists, rationality means an individual possesses stable preferences that are both complete and transitive.
The technical assumption that preference relations are continuous is needed to ensure the existence of a utility function. Although microeconomic theory can continue without this assumption, it would make comparative statics impossible since there is no guarantee that the resulting utility function would be differentiable.
Microeconomic theory progresses by defining a competitive budget set which is a subset of the consumption set. It is at this point that economists make the technical assumption that preferences are locally non-satiated. Without the assumption of LNS (local non-satiation) there is no 100% guarantee but there would be a rational rise in individual utility. With the necessary tools and assumptions in place the utility maximization problem (UMP) is developed.
The utility maximization problem is the heart of consumer theory. The utility maximization problem attempts to explain the action axiom by imposing rationality axioms on consumer preferences and then mathematically modeling and analyzing the consequences. The utility maximization problem serves not only as the mathematical foundation of consumer theory but as a metaphysical explanation of it as well. That is, the utility maximization problem is used by economists to not only explain what or how individuals make choices but why individuals make choices as well.
The utility maximization problem is a constrained optimization problem in which an individual seeks to maximize utility subject to a budget constraint. Economists use the extreme value theorem to guarantee that a solution to the utility maximization problem exists. That is, since the budget constraint is both bounded and closed, a solution to the utility maximization problem exists. Economists call the solution to the utility maximization problem a Walrasian demand function or correspondence.
The utility maximization problem has so far been developed by taking consumer tastes (i.e. consumer utility) as the primitive. However, an alternative way to develop microeconomic theory is by taking consumer choice as the primitive. This model of microeconomic theory is referred to as revealed preference theory.
The theory of supply and demand usually assumes that markets are perfectly competitive. This implies that there are many buyers and sellers in the market and none of them have the capacity to significantly influence prices of goods and services. In many real-life transactions, the assumption fails because some individual buyers or sellers have the ability to influence prices. Quite often, a sophisticated analysis is required to understand the demand-supply equation of a good model. However, the theory works well in situations meeting these assumptions.
Mainstream economics does not assume a priori that markets are preferable to other forms of social organization. In fact, much analysis is devoted to cases where market failures lead to resource allocation that is suboptimal and creates deadweight loss. A classic example of suboptimal resource allocation is that of a public good. In such cases, economists may attempt to find policies that avoid waste, either directly by government control, indirectly by regulation that induces market participants to act in a manner consistent with optimal welfare, or by creating "missing markets" to enable efficient trading where none had previously existed.
This is studied in the field of collective action and public choice theory. "Optimal welfare" usually takes on a Paretian norm, which is a mathematical application of the Kaldor–Hicks method. This can diverge from the Utilitarian goal of maximizing utility because it does not consider the distribution of goods between people. Market failure in positive economics (microeconomics) is limited in implications without mixing the belief of the economist and their theory.
The demand for various commodities by individuals is generally thought of as the outcome of a utility-maximizing process, with each individual trying to maximize their own utility under a budget constraint and a given consumption set.
The study of microeconomics involves several "key" areas:
Supply and demand is an economic model of price determination in a perfectly competitive market. It concludes that in a perfectly competitive market with no externalities, per unit taxes, or price controls, the unit price for a particular good is the price at which the quantity demanded by consumers equals the quantity supplied by producers. This price results in a stable economic equilibrium.
Elasticity is the measurement of how responsive an economic variable is to a change in another variable. Elasticity can be quantified as the ratio of the change in one variable to the change in another variable, when the later variable has a causal influence on the former. It is a tool for measuring the responsiveness of a variable, or of the function that determines it, to changes in causative variables in unitless ways. Frequently used elasticities include price elasticity of demand, price elasticity of supply, income elasticity of demand, elasticity of substitution or constant elasticity of substitution between factors of production and elasticity of intertemporal substitution.
Consumer demand theory relates preferences for the consumption of both goods and services to the consumption expenditures; ultimately, this relationship between preferences and consumption expenditures is used to relate preferences to consumer demand curves. The link between personal preferences, consumption and the demand curve is one of the most closely studied relations in economics. It is a way of analyzing how consumers may achieve equilibrium between preferences and expenditures by maximizing utility subject to consumer budget constraints.
Production theory is the study of production, or the economic process of converting inputs into outputs. Production uses resources to create a good or service that is suitable for use, gift-giving in a gift economy, or exchange in a market economy. This can include manufacturing, storing, shipping, and packaging. Some economists define production broadly as all economic activity other than consumption. They see every commercial activity other than the final purchase as some form of production.
The cost-of-production theory of value states that the price of an object or condition is determined by the sum of the cost of the resources that went into making it. The cost can comprise any of the factors of production: labour, capital, land, entrepreneur. Technology can be viewed either as a form of fixed capital (e.g. plant) or circulating capital (e.g. intermediate goods).
In the mathematical model for the cost of production, the short-run total cost is equal to fixed cost plus total variable cost. The fixed cost refers to the cost that is incurred regardless of how much the firm produces. The variable cost is a function of the quantity of an object being produced.
The economic idea of opportunity cost is closely related to the idea of time constraints. You can do only one thing at a time, which means that, inevitably, you’re always giving up other things.
The opportunity cost of any activity is the value of the next-best alternative thing you may have done instead. Opportunity cost depends only on the value of the next-best alternative. It doesn’t matter whether you have 5 alternatives or 5,000.
Opportunity costs can tell you when not to do something as well as when to do something. For example, you may like waffles, but you like chocolate even more. If someone offers you only waffles, you’re going to take it. But if you’re offered waffles or chocolate, you’re going to take the chocolate. The opportunity cost of eating waffles is sacrificing the chance to eat chocolate. Because the cost of not eating the chocolate is higher than the benefits of eating the waffles, it makes no sense to choose waffles. Of course, if you choose chocolate, you’re still faced with the opportunity cost of giving up having waffles. But you’re willing to do that because the waffle's opportunity cost is lower than the benefits of the chocolate. Opportunity costs are unavoidable constraints on behaviour because you have to decide what’s best and give up the next-best alternative.
The market structure can have several types of interacting market systems. Different forms of markets are a feature of capitalism and market socialism, with advocates of state socialism often criticizing markets and aiming to substitute or replace markets with varying degrees of government-directed economic planning.
Competition acts as a regulatory mechanism for market systems, with government providing regulations where the market cannot be expected to regulate itself. One example of this is with regards to building codes, which if absent in a purely competition regulated market system, might result in several horrific injuries or deaths to be required before companies would begin improving structural safety, as consumers may at first not be as concerned or aware of safety issues to begin putting pressure on companies to provide them, and companies would be motivated not to provide proper safety features due to how it would cut into their profits.
Some examples of markets:
Perfect competition is a situation in which numerous small firms producing identical products compete against each other in a given industry. Perfect competition leads to firms producing the socially optimal output level at the minimum possible cost per unit. Firms in perfect competition are "price takers" (they do not have enough market power to profitably increase the price of their goods or services). A good example would be that of digital marketplaces, such as eBay, on which many different sellers sell similar products to many different buyers. Consumers in a perfect competitive market have perfect knowledge about the products that are being sold in this market.
In economic theory, imperfect competition is a type of market structure showing some but not all features of competitive markets.
Monopolistic competition is a situation in which many firms with slightly different products compete. Production costs are above what may be achieved by perfectly competitive firms, but society benefits from the product differentiation. Examples of industries with market structures similar to monopolistic competition include restaurants, cereal, clothing, shoes, and service industries in large cities.
A monopoly is a market structure in which a market or industry is dominated by a single supplier of a particular good or service. Because monopolies have no competition they tend to sell goods and services at a higher price and produce below the socially optimal output level. However, not all monopolies are a bad thing, especially in industries where multiple firms would result in more costs than benefits (i.e. natural monopolies).
An oligopoly is a market structure in which a market or industry is dominated by a small number of firms (oligopolists). Oligopolies can create the incentive for firms to engage in collusion and form cartels that reduce competition leading to higher prices for consumers and less overall market output. Alternatively, oligopolies can be fiercely competitive and engage in flamboyant advertising campaigns.
A monopsony is a market where there is only one buyer and many sellers.
An oligopsony is a market where there are a few buyers and many sellers.
Game theory is a major method used in mathematical economics and business for modeling competing behaviors of interacting agents. The term "game" here implies the study of any strategic interaction between people. Applications include a wide array of economic phenomena and approaches, such as auctions, bargaining, mergers & acquisitions pricing, fair division, duopolies, oligopolies, social network formation, agent-based computational economics, general equilibrium, mechanism design, and voting systems, and across such broad areas as experimental economics, behavioral economics, information economics, industrial organization, and political economy.
Labor economics seeks to understand the functioning and dynamics of the markets for wage labor. Labor markets function through the interaction of workers and employers. Labor economics looks at the suppliers of labor services (workers), the demands of labor services (employers), and attempts to understand the resulting pattern of wages, employment, and income. In economics, labor is a measure of the work done by human beings. It is conventionally contrasted with such other factors of production as land and capital. There are theories which have developed a concept called human capital (referring to the skills that workers possess, not necessarily their actual work), although there are also counter posing macro-economic system theories that think human capital is a contradiction in terms.
Welfare economics is a branch of economics that uses microeconomics techniques to evaluate well-being from allocation of productive factors as to desirability and economic efficiency within an economy, often relative to competitive general equilibrium. It analyzes social welfare, however measured, in terms of economic activities of the individuals that compose the theoretical society considered. Accordingly, individuals, with associated economic activities, are the basic units for aggregating to social welfare, whether of a group, a community, or a society, and there is no "social welfare" apart from the "welfare" associated with its individual units.
Information economics or the economics of information is a branch of microeconomic theory that studies how information and information systems affect an economy and economic decisions. Information has special characteristics. It is easy to create but hard to trust. It is easy to spread but hard to control. It influences many decisions. These special characteristics (as compared with other types of goods) complicate many standard economic theories. The economics of information has recently become of great interest to many - possibly due to the rise of information based companies inside the technology industry. From a game theory approach, we can loosen the usual constraints that agents have complete information to further examine the consequences of having incomplete information. This gives rise to many results which are applicable to real life situations. For example, if one does loosen this assumption, then it is possible to scrutinize the actions of agents in situations of uncertainty. It is also possible to more fully understand the impacts - both positive and negative - of agents seeking out or acquiring information.
Applied microeconomics includes a range of specialized areas of study, many of which draw on methods from other fields. Industrial organization examines topics such as the entry and exit of firms, innovation, and the role of trademarks. Labor economics examines wages, employment, and labor market dynamics. Financial economics examines topics such as the structure of optimal portfolios, the rate of return to capital, econometric analysis of security returns, and corporate financial behavior. Public economics examines the design of government tax and expenditure policies and economic effects of these policies (e.g., social insurance programs). Political economy examines the role of political institutions in determining policy outcomes. Health economics examines the organization of health care systems, including the role of the health care workforce and health insurance programs. Education economics examines the organization of education provision and its implication for efficiency and equity, including the effects of education on productivity. Urban economics, which examines the challenges faced by cities, such as sprawl, air and water pollution, traffic congestion, and poverty, draws on the fields of urban geography and sociology. Law and economics applies microeconomic principles to the selection and enforcement of competing legal regimes and their relative efficiencies. Economic history examines the evolution of the economy and economic institutions, using methods and techniques from the fields of economics, history, geography, sociology, psychology, and political science.
Game theory is the main way economists [sic] understands the behavior of firms within this market structure.
Advanced Placement Microeconomics (or AP Microeconomics) is a course offered by the College Board as part of the Advanced Placement Program for high school students interested in college-level coursework in microeconomics and/or gaining advanced standing in college. The course begins with a study of fundamental economic concepts such as scarcity, opportunity costs, production possibilities, specialization, and comparative advantage. Major topics include the nature and functions of product markets; factor markets; and efficiency, equity, and the role of government. AP Microeconomics is often taken in conjunction with or after AP Macroeconomics.Aggregation problem
An aggregate in economics is a summary measure describing a market or economy. The aggregation problem is the difficult problem of finding a valid way to treat an empirical or theoretical aggregate as if it reacted like a less-aggregated measure, say, about behavior of an individual agent as described in general microeconomic theory. Examples of aggregates in micro- and macroeconomics relative to less aggregated counterparts are:
Food vs. apples
Price level and real GDP vs. the price and quantity of apples
Capital stock vs. the value of computers of a certain type and the value of steam shovels
Money supply vs. paper currency
General unemployment rate vs. the unemployment rate of civil engineersStandard theory uses simple assumptions to derive general, and commonly accepted, results such as the law of demand to explain market behavior. An example is the abstraction of a composite good. It considers the price of one good changing proportionately to the composite good, that is, all other goods. If this assumption is violated and the agents are subject to aggregated utility functions, restrictions on the latter are necessary to yield the law of demand. The aggregation problem emphasizes:
How broad such restrictions are in microeconomics
Use of broad factor inputs ("labor" and "capital"), real "output", and "investment", as if there was only a single such aggregate is without a solid foundation for rigorously deriving analytical results.Franklin Fisher notes that this has not dissuaded macroeconomists from continuing to use such concepts.All-pay auction
In economics and game theory, an all-pay auction is an auction in which every bidder must pay regardless of whether they win the prize, which is awarded to the highest bidder as in a conventional auction.
In an all-pay auction, the Nash equilibrium is such that each bidder plays a mixed strategy and their expected pay-off is zero. The seller's expected revenue is equal to the value of the prize. However, some economic experiments have shown that over-bidding is common. That is, the seller's revenue frequently exceeds that of the value of the prize, and in repeated games even bidders that win the prize frequently will most likely take a loss in the long run.American Economic Journal
The American Economic Journal is a group of four peer-reviewed academic journals published by the American Economic Association. The names of the individual journals consist of the prefix American Economic Journal with a descriptor of the field attached. The four field journals which started in 2009 are Applied Economics, Economic Policy, Macroeconomics, and Microeconomics.Blackstartup
BlackStartup was a crowdfunding platform that allows entrepreneurs to market their business or project and solicit backers for funding. BlackStartup is the first crowdfunding site focused on entrepreneurship in the African-American community.
The site was founded in 2013 by a group of Morehouse College graduates who are also members of Omega Psi Phi fraternity.
As of August 2017, the site is offline and up for sale.Budget set
A budget set or opportunity set includes all possible consumption bundles that someone can afford given the prices of goods and the person's income level. The budget set is bounded above by the budget line.
Graphically speaking, all the consumption bundles that lie inside the budget constraint and on the budget constraint form the budget set or opportunity set.
By most definitions, budget sets must be compact and convex.Deadlock (game theory)
In game theory, Deadlock is a game where the action that is mutually most beneficial is also dominant. This provides a contrast to the Prisoner's Dilemma where the mutually most beneficial action is dominated. This makes Deadlock of rather less interest, since there is no conflict between self-interest and mutual benefit.Economic efficiency
In microeconomics, economic efficiency is, roughly speaking, a situation in which nothing can be improved without something else being hurt. Depending on the context, it is usually one of the following two related concepts:
Allocative or Pareto efficiency: any changes made to assist one person would harm another.
Productive efficiency: no additional output of one good can be obtained without decreasing the output of another good, and production proceeds at the lowest possible average total cost.These definitions are not equivalent: a market or other economic system may be allocatively but not productively efficient, or productively but not allocatively efficient. There are also other definitions and measures. All characterizations of economic efficiency are encompassed by the more general engineering concept that a system is efficient or optimal when it maximizes desired outputs (such as utility) given available inputs.Goods
In economics, goods are materials that satisfy human wants and provide utility, for example, to a consumer making a purchase of a satisfying product. A common distinction is made between goods that are tangible property, and services, which are non-physical. A good may be a consumable item that is useful to people but scarce in relation to its demand, so that human effort is required to obtain it. In contrast, free goods, such as air, are naturally in abundant supply and need no conscious effort to obtain them. Personal goods are things such as televisions, living room furniture, wallets, cellular telephones, almost anything owned or used on a daily basis that is not food related. Commercial goods are construed as any tangible product that is manufactured and then made available for supply to be used in an industry of commerce. Commercial goods could be tractors, commercial vehicles, mobile structures, airplanes and even roofing materials. Commercial and personal goods as categories are very broad and cover almost everything a person sees from the time they wake up in their home, on their commute to work to their arrival at the workplace.
Commodities may be used as a synonym for economic goods but often refer to marketable raw materials and primary products.Although in economic theory all goods are considered tangible, in reality certain classes of goods, such as information, only take intangible forms. For example, among other goods an apple is a tangible object, while news belongs to an intangible class of goods and can be perceived only by means of an instrument such as print or television.Hal Varian
Hal Ronald Varian (born March 18, 1947 in Wooster, Ohio) is an economist specializing in microeconomics and information economics. He is the chief economist at Google and he holds the title of emeritus professor at the University of California, Berkeley where he was founding dean of the School of Information.Macroeconomics
Macroeconomics (from the Greek prefix makro- meaning "large" + economics) is a branch of economics dealing with the performance, structure, behavior, and decision-making of an economy as a whole. This includes regional, national, and global economies. Macroeconomists study aggregated indicators such as GDP, unemployment rates, national income, price indices, and the interrelations among the different sectors of the economy to better understand how the whole economy functions. They also develop models that explain the relationship between such factors as national income, output, consumption, unemployment, inflation, saving, investment, energy, international trade, and international finance.
While macroeconomics is a broad field of study, there are two areas of research that are emblematic of the discipline: the attempt to understand the causes and consequences of short-run fluctuations in national income (the business cycle), and the attempt to understand the determinants of long-run economic growth (increases in national income). Macroeconomic models and their forecasts are used by governments to assist in the development and evaluation of economic policy.
Macroeconomics and microeconomics, a pair of terms coined by Ragnar Frisch, are the two most general fields in economics. In contrast to macroeconomics, microeconomics is the branch of economics that studies the behavior of individuals and firms in making decisions and the interactions among these individuals and firms in narrowly-defined markets.Mandeville's paradox
Mandeville's paradox is named after Bernard Mandeville, who posits that actions which may be qualified as vicious with regard to individuals have benefits for society as a whole. This is alluded to in the subtitle of his most famous work, The Fable of The Bees: ‘Private Vices, Public Benefits’. He states that "Fraud, Luxury, and Pride must live; Whilst we the Benefits receive.") (The Fable of the Bees, ‘The Moral’).
The philosopher and economist Adam Smith opposes this (although he defends a moderated version of this line of thought in his theory of the invisible hand), since Mandeville fails, in his opinion, to distinguish between vice and virtue (The Theory of Moral Sentiments, Part VII, Section II, Chapter 4 (‘Of licentious systems’)).Markov strategy
In game theory, a Markov strategy is one that depends only on state variables that summarize the history of the game in one way or another. For instance, a state variable can be the current play in a repeated game, or it can be any interpretation of a recent sequence of play.
A profile of Markov strategies is a Markov perfect equilibrium if it is a Nash equilibrium in every state of the game.Microfoundations
In economics, the microfoundations are the microeconomic behavior of individual agents, such as households or firms, that underpins a macroeconomic theory.Most early macroeconomic models, including early Keynesian models, were based on hypotheses about relationships between aggregate quantities, such as aggregate output, employment, consumption, and investment. Critics and proponents of these models disagreed as to whether these aggregate relationships were consistent with the principles of microeconomics. Therefore, in recent decades macroeconomists have attempted to combine microeconomic models of household and firm behavior to derive the relationships between macroeconomic variables. Today, many macroeconomic models, representing different theoretical points of view, are derived by aggregating microeconomic models allowing economists to test them both with macroeconomic and microeconomic data.Monopolistic competition
Monopolistic competition is a type of imperfect competition such that many producers sell products that are differentiated from one another (e.g. by branding or quality) and hence are not perfect substitutes. In monopolistic competition, a firm takes the prices charged by its rivals as given and ignores the impact of its own prices on the prices of other firms. In the presence of coercive government, monopolistic competition will fall into government-granted monopoly. Unlike perfect competition, the firm maintains spare capacity. Models of monopolistic competition are often used to model industries. Textbook examples of industries with market structures similar to monopolistic competition include restaurants, cereal, clothing, shoes, and service industries in large cities. The "founding father" of the theory of monopolistic competition is Edward Hastings Chamberlin, who wrote a pioneering book on the subject, Theory of Monopolistic Competition (1933). Joan Robinson published a book The Economics of Imperfect Competition with a comparable theme of distinguishing perfect from imperfect competition.
Monopolistically competitive markets have the following characteristics:
There are many producers and many consumers in the market, and no business has total control over the market price.Consumers perceive that there are non-price differences among the competitors' products.There are few barriers to entry and exit.Producers have a degree of control over price.The long-run characteristics of a monopolistically competitive market are almost the same as a perfectly competitive market. Two differences between the two are that monopolistic competition produces heterogeneous products and that monopolistic competition involves a great deal of non-price competition, which is based on subtle product differentiation. A firm making profits in the short run will nonetheless only break even in the long run because demand will decrease and average total cost will increase. This means in the long run, a monopolistically competitive firm will make zero economic profit. This illustrates the amount of influence the firm has over the market; because of brand loyalty, it can raise its prices without losing all of its customers. This means that an individual firm's demand curve is downward sloping, in contrast to perfect competition, which has a perfectly elastic demand schedule.N-player game
In game theory, an n-player game is a game which is well defined for any number of players. This is usually used in contrast to standard 2-player games that are only specified for two players. In defining n-player games, game theorists usually provide a definition that allow for any (finite) number of players. Changing games from 2-player games to n-player games entails some concerns.Production set
A production set is the set of all combinations of inputs and outputs that comprise a technologically feasible way to produce. It is used as part of profit maximization calculations.Self-confirming equilibrium
In game theory, self-confirming equilibrium is a generalization of Nash equilibrium for extensive form games, in which players correctly predict the moves their opponents make, but may have misconceptions about what their opponents would do at information sets that are never reached when the equilibrium is played. Informally, self-confirming equilibrium is motivated by the idea that if a game is played repeatedly, the players will revise their beliefs about their opponents' play if and only if they observe these beliefs to be wrong.
Consistent self-confirming equilibrium is a refinement of self-confirming equilibrium that further requires that each player correctly predicts play at all information sets that can be reached when the player's opponents, but not the player herself, deviate from their equilibrium strategies. Consistent self-confirming equilibrium is motivated by learning models in which players are occasionally matched with "crazy" opponents, so that even if they stick to their equilibrium strategy themselves, they eventually learn the distribution of play at all information sets that can be reached if their opponents deviate.Supply and demand
In microeconomics, supply and demand is an economic model of price determination in a market. It postulates that, holding all else equal, in a competitive market, the unit price for a particular good, or other traded item such as labor or liquid financial assets, will vary until it settles at a point where the quantity demanded (at the current price) will equal the quantity supplied (at the current price), resulting in an economic equilibrium for price and quantity transacted.