Neoclassical economics

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Neoclassical economics refers to a general approach (a "metatheory") to economics based on supply and demand which depends on individuals (or any economic agent) operating rationally, each seeking to maximize their individual utility or profit by making choices based on available information. Mainstream economics is largely neoclassical in its assumptions, at least at the microeconomic level. There have been many critiques of neoclassical economics, often incorporated into newer versions of neoclassical theory as circumstances change.

Contents

1 Overview
2 Origins of neoclassical economics
3 Further developments
4 Criticisms of neoclassical economics
5 See also
6 External links

Overview

Neoclassical economics is the singular element of several schools of thought in economics. There is not complete agreement on what is meant by neoclassical economics, and the result is a wide range of neoclassical approaches to various problem areas and domains -- ranging from neoclassical theories of labor to neoclassical theories of demographic changes.

As expressed by E. Roy Weintraub, neoclassical economics rests on three assumptions, although certain branches of neoclassical theory may have different approaches:

People have rational preferences among outcomes that can be identified and associated with a value.
Individuals maximize utility and firms maximize profits.
People act independently on the basis of full and relevant information.

From these three assumptions, neoclassical economists have built a structure to understand the allocation of scarce resources among alternative ends -- in fact understanding such allocation is often considered the definition of economics to neoclassical theorists. Here's how William Stanley Jevons presented the basic problem of economics:

Given, a certain population, with certain needs and powers of production, in possession of certain lands and other sources of material: required, the mode of employing their labour which will maximize the utility of their produce.

From the basic assumptions of neoclassical economics comes a wide range of theories about various areas of economic activity. For example, profit maximization lies behind the neoclassical theory of the firm, while the derivation of demand curves leads to an understanding of consumer goods, and the supply curve allows an analysis of the factors of production. Utility maximization is the source for the neoclassical theory of consumption, the derivation of demand curves for consumer goods, and the derivation of factor supply curves and reservation demand.

Neoclassical economics emphasizes equilibria, where equilibria are the solutions of individual maximization problems. Regularities in economies are explained by methodological individualism, the doctrine that all economic phenomena can be ultimately explained by aggregating over the behavior of individuals. The emphasis is on microeconomics. Institutions, which might be considered as prior to and conditioning individual behavior, are de-emphasized. Economic subjectivism accompanies these emphases. See also general equilibrium.

Origins of neoclassical economics

Classical economics, developed in the 18th and 19th centuries, focused on value theory and distribution theory. The value of a product was thought to depend on the costs involved in producing that product. Goods were distributed in an economy, it was assumed, in the same way that costs were distributed -- thus, a landlord would receive more goods than a tenant farmer because the landlord bore most of the cost. This classic approach included the work of Adam Smith and David Ricardo. However, some economists began to say that prices for a product did not always reflect the expected value as indicated by the costs of a product. They proposed a theory that the cost of a product was not expressed in its price, but that this can be explained with differences in "utility." Economists began to explore the way that elements such as supply and demand affected price, and neo-classical economics gradually came into being.

Neoclassical economics is conventionally dated from William Stanley Jevons's Theory of Political Economy (1871), Carl Menger's Principles of Economics (1871), and Leon Walras's Elements of Pure Economics (1874 – 1877). These three economists have been said to have promulgated the marginal utility revolution, or Neoclassical Revolution. Historians of economics and economists have debated:

Whether utility or marginalism was more essential to this revolution (whether the noun or the adjective in the phrase "marginal utility" is more important)

Whether there was a revolutionary change of thought or merely a gradual development and change of emphasis from their predecessors

Whether grouping these economists together disguises differences more important than their similarities.

In particular, Walras was more interested in the interaction of markets than in explaining the individual psyche through a hedonistic psychology. Jevons saw his economics as an application and development of Jeremy Bentham's utilitarianism and never had a fully developed general equilibrium theory. Menger emphasized disequilibrium and the discrete. Menger had a philosophical objection to the use of mathematics in economics, while the other two modeled their theories after 19th century mechanics.

Alfred Marshall's textbook, Principles of Economics (1890), was the dominant textbook in England a generation later. Marshall's influence extended elsewhere; Italians would compliment Maffeo Pantaleoni by calling him the "Marshall of Italy". Marshall thought classical economics attempted to explain prices by the cost of production. He asserted that the neoclassicals went too far in correcting this imbalance by overemphasizing utility and demand. Marshall thought the question of whether supply or demand was more important was analogous to the pointless question of which blade of a scissors did the cutting.

Marshall explained prices by the intersection of supply and demand curves. The introduction of different market "periods" was an important innovation of Marshall's:

Market period. The goods produced for sale on the market are taken as given data, e.g. in a fish market. Prices quickly adjust to clear markets.
Short period. Industrial capacity is taken as given. The level of output, the level of employment, the inputs of raw materials, and prices fluctuate to equate marginal cost and marginal revenue, where profits are maximized. Economic rents exist in short period equilibrium for fixed factors, and the rate of profit is not equated across sectors.
Long period. The stock of capital goods, such as factories and machines, is not taken as given. Profit-maximizing equilibria determine both industrial capacity and the level at which it is operated.
Very long period. Technology, population trends, habits and customs are not taken as given, but allowed to vary in very long period models.

Marshall took supply and demand as stable functions and extended supply and demand explanations of prices to all runs. He argued supply was easier to vary in longer runs, and thus became a more important determinate of price in the very long run.

Further developments

An important change in neoclassical economics occurred around 1933. Joan Robinson and Edward H. Chamberlin, with the near simultaneous publication of their respective books, The Economics of Imperfect Competition (1933) and The Theory of Monopolistic Competition (1933), introduced models of imperfect competition. Theories of market forms and industrial organization grew out of this work. They also emphasized certain tools, such as the marginal revenue curve.

Joan Robinson's work on imperfect competition, at least, was a response to certain problems of Marshallian partial equilibrium theory highlighted by Piero Sraffa. Anglo-American economists also responded to these problems by turning towards general equilibrium theory, developed on the European continent by Walras and Vilfredo Pareto. J. R. Hicks's Value and Capital (1939) was influential in introducing his English-speaking colleagues to these traditions. He, in turn, was influenced by the Austrian School economist Friedrich Hayek's move to the London School of Economics, where Hicks then studied.

These developments were accompanied by the introduction of new tools, such as indifference curves and the theory of ordinal utility. The level of mathematical sophistication of neoclassical economics increased. Paul Samuelson's Foundations of Economic Analysis (1947) contributed to this increase in formal rigor.

The interwar period in American economics has been argued to have been pluralistic, with neoclassical economics and institutionalism competing for allegiance. Frank Knight, an early Chicago school economist attempted to combine both schools. But this increase in mathematics was accompanied by greater dominance of neoclassical economics in Anglo-American universities after World War II.

Hicks' book had two main parts. The second, which was arguably not immediately influential, presented a model of temporary equilibrium. Hicks was influenced directly by Hayek's notion of intertemporal coordination and paralleled by earlier work by Lindhal. This was part of an abandonment of disaggregated long run models. This trend probably reached its culmination with the Arrow-Debreu model of intertemporal equilibrium. The Arrow-Debreu model has canonical presentations in Gerard Debreu's Theory of Value (1959) and in Arrow and Hahn.

Many of these developments were against the backdrop of improvements in both econometrics, that is the ability to measure prices and changes in goods and services, as well as their aggregate quantities, and in the creation of macroeconomics, or the study of whole economies. The attempt to combine neo-classical microeconomics and Keynesian macroeconomics would lead to the neo-classical synthesis which has been the dominant paradigm of economic reasoning in English speaking countries since the 1950's. Hicks and Arrow were for example essential in the development of Keynesian economics.

Macroeconomics influenced the neo-classical synthesis from the other direction, undermining foundations of classical economic theory such as Say's Law, and assumptions about political economy such as the necessity for a hard money standard. These developments are reflected in neo-classical theory by the search for the occurrence in markets of the equilibrium conditions of pareto optimality and self-sustainability.

Criticisms of neoclassical economics

Neoclassical economics is sometimes criticised for having a normative bias. In this view, it does not focus on explaining actual economies, but instead on describing a "utopia" in which Pareto optimality obtains. Key assumptions of neoclassical economics which are widely criticised as unrealistic include:

The focus on individuals in the economy may obscure analysis of wider long term issues, such as whether the economic system is desirable and stable on a finite planet of limited natural capital.
The assumption that individuals act rationally may be viewed as ignoring important aspects of human behavior. Many see the "economic man" as being demonstrably different to a real man on the real earth -- they are not human, and are increasingly criticized for not being human. The assumption of rational expectations which has been introduced in some more modern neo-classical models (sometimes also called new classical) may also be strongly criticised on the grounds of realism.
Large corporations might perhaps come closer to the neoclassical ideal of profit maximisation, but this is not necessarily viewed as desirable if this comes at the expense of a "locust-like" neglect of wider social issues.
Problems with making the neoclassical general equilibrium theory compatible with an economy that develops over time and includes capital goods. This was explored in a major debate in the 1960s - the Cambridge Capital Controversy - about the validity of neoclassical economics, with an emphasis on the economic growth, capital, aggregate theory, and the marginal productivity theory of distribution. There were also internal attempts by neoclassical economists to extend the Arrow-Debreu model to disequilibrium investigations of stability and uniqueness. However a result known as the Sonnenschein-Mantel-Debreu theorem suggests that the assumptions that must be made to insure that the equilibrium is stable and unique are quite restrictive.
In the opinion of some, these developments have found fatal weaknesses in neoclassical economics. Economists, however, have continued to use highly mathematical models, and many equate neoclassical economics with economics, unqualified. Mathematical models include those in game theory, linear programming, and econometrics, many of which might be considered non-neoclassical. So economists often refer to what has evolved out of neoclassical economics as "mainstream economics". Critics of neoclassical economics are divided in those who think that highly mathematical method is inherenly wrong and those who think that mathematical method is potentially good even though if contemporary methods have problems.
The basic theory about downward sloping aggregate demand curve for any product is critizised for its allegedly too big assumption, that individual consumers have identical preferences which do not change when the wealth of individual changes (some critics of neoclassical claim, that these assumptions are not told for young students until their faith in the discipline is strong enough). In general, allegedly too unrealistic assumptions are one of the most common criticisms towards neoclassical economics. For example, many theories assume perfect knowledge for market actors and the most common theory of finance markets assumes that debts are always paid back and that any actor can raise as much loan as he wants at any given point of time.
The basic theory of production in neoclassical economics is criticized of assuming wrongly rationales for producers. According to the theory, increasing production costs are the reason for producers not to produce over certain amount. Some empirical counter arguments claim that most of producers in economy are not doing their production decisions in the light of increasing production costs (for example, they often may have additional capacity that could be taken into use, if producing more was desirable).
Often at individual levels, variables such as supply and demand, which are independent, are (allegedly wrongly) assumed to be independent also at aggregate level. This criticism has been applied to many central theories of neoclassical economics.
Theory of perfect competition is critized by claiming that it wrongly assumes that demand curve for one firm is flat, while as a matter of fact, it has to be (very) slightly bending, since in that theory, the demand curve for individual firm is a part of aggregate demand curve that is not flat. Taking this into account would ruin the theory.
The critique of the assumption of rationality is not confined to social theorists and ecologists. Many economists, even contemporaries, have criticized this vision of economic man. Thorstein Veblen put it most sardonically:

lightning calculator of pleasures and pains, who oscillates like a homogeneous globule of desire of happiness under the impulse of stimuli that shift about the area, but leave him intact.

Herbert Simon's theory of bounded rationality has probably been the most influential of the heterodox approaches. Is economic man a first approximation to a more realistic psychology, an approach only valid in some sphere of human lives, or a general methodological principle for economics? Early neoclassical economists often leaned toward the first two appoaches, but the latter has become prevalent.

Neoclassical economics is also often seen as relying too heavily on complex mathematical models, such as those used in general equilibrium theory, without enough regard to whether these actually describe the real economy. Many see an attempt to model a system as complex as a modern economy by a mathematical model as unrealistic and doomed to failure. Famous answer to this criticism is Milton Friedman's claim that theories should be judged by their ability to predict events rather than by the realisticity of their assumptions. Naturally, many claim that neoclassical economics (as well as other branches of economics) has not been very good at predicting events.
Critics of neoclassical models accuse it of copying of 19th century mechanics and the "clockwork" model of society which seems to justify elite privileges as arising "naturally" from the social order based on economic competititions. This is echoed by modern critics in the anti-globalization movement who often blame the neoclassical theory, as it has been applied by the IMF in particular, for inequities in global debt and trade relations. They assert it ignores the complexity of nature and of human creativity, and seeks mechanical ideas like equilibrium:

And in Poinset's Elements de Statique..., which was a textbook on the theory of mechanics bristling with systems of simultaneous equations to represent, among other things, the mechanical equilibrium of the solar system, Walras found a pattern for representing the catallactic equilibrium of the market system. (William Jaffe)

It is fair to say that many (but not all) of these criticisms can only be directed towards a subset of the neoclassical models. Eg, there are many neoclassical models where unregulated markets fail to achieve pareto-optimality and there has recently been an increased interest in modelling bounded rationality.

External links

[Neoclassical economics] from the Concise Library of Economics
[Introduction to neoclassical economics] at Drexel

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