Macroeconomics

Circulation in macroeconomics

Macroeconomics (from Greek prefix "macr(o)-" meaning "large" + "economics") is a branch of economics dealing with the performance, structure, behavior, and decision-making of the entire economy. This includes a national, regional, or global economy. With microeconomics, macroeconomics is one of the two most general fields in economics.

Macroeconomists study aggregated indicators such as GDP, unemployment rates, and price indices to understand how the whole economy functions. Macroeconomists develop models that explain the relationship between such factors as national income, output, consumption, unemployment, inflation, savings, investment, international trade and international finance. In contrast, microeconomics is primarily focused on the actions of individual agents, such as firms and consumers, and how their behavior determines prices and quantities in specific markets. 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 both governments and large corporations to assist in the development and evaluation of economic policy and business strategy.

Basic macroeconomic concepts

Macroeconomics encompasses a variety of concepts and variables, but three are central topics for macroeconomic research. Macroeconomic theories usually relate the phenomena of output, unemployment, and inflation. Outside of macroeconomic theory, these topics are also extremely important to all economic agents including workers, consumers, and producers.

Output and income

National output is the total value of everything a country produces in a given time period. Since everything that is produced and sold produces income, output and income are usually considered to be equivalent and the two terms are often used interchangeably. Output can be measured as total income, or, it can be viewed from the production side and measured as the total value of final goods and services or the sum of all value added in the economy. Macroeconomic output is usually measured by Gross Domestic Product (GDP) or one of the other national accounts. Economists interested in long-run increases in output study economic growth. Advances in technology, increases in machinery and other capital, and better education and human capital all lead to increased economic output overtime. However, output does not always increase consistently. Business cycles can cause short-term drops in output called recessions. Economists look for macroeconomic policies that prevent economies from slipping into recessions and that lead to faster long-term growth.

Unemployment

The amount of unemployment in an economy is measured by the unemployment rate, the percentage of workers without jobs in the labor force. The labor force only includes worker's actively looking for jobs. People who are retired, persuing education, or discouraged from seeking work by a lack of job prospects are excluded from the labor force.

Unemployment can be generally broken down into several types based related to different causes. Classical unemployment occurs when wages are too high for employers to be willing to hire more workers. Wages may be too high because of minimum wage laws or union activity. Consistent with classical unemployment, frictional unemployment occurs when appropriate job vacancies exist for a worker, but the length of time needed to search for and find the job leads to a period of unemployment. Structural unemployment covers a variety of possible causes of unemployment including a mismatch between workers' skills and the skills required for open jobs. Large amounts of structural unemployment can occur when an economy is transitioning industries and workers find their previous set of skills are no longer in demand. Structural unemployment is similar to frictional unemployment since both reflect the problem of matching workers with job vacancies, but structural unemployment covers the time needed to acquire new skills not just the short term search process. While some types of unemployment may occur regardless of the condition of the economy, cyclical unemployment occurs when growth stagnates. Okun's law represents the empirical relationship between unemployment and economic growth. The original version of Okun's law states that a 3% increase in output would lead to a 1% decrease in unemployment.

Inflation and deflation

A general price increase across the entire economy is called inflation. When prices decrease, there is deflation. Economists measure these changes in prices with price indexes. Inflation can occur when an economy becomes overheated and grows too quickly. Similarly, a declining economy can lead to deflation. Central bankers, who control a country's money supply, try to avoid changes in price level by using monetary policy. Raising interest rates or reducing the supply of money in an economy will reduce inflation. Inflation can lead to increased uncertainty and other negatives consequences. Deflation can lower economic output. Central bankers try to stabilize prices to protect economies from the negative consequences of price changes.

Macroeconomic policies

To try to avoid major economic shocks, such as The Great Depression, governments make adjustments through policy changes they hope will stabilize the economy. Governments believe the success of these adjustments is necessary to maintain stability and continue growth. This economic management is achieved through two types of governmental strategies:

• Fiscal policy
• Monetary policy

Development of macroeconomic theory

Main article: History of macroeconomic thought

Origins and General Statements

Whilst there is a degree of uncertancy about macroeconomics, it is regarded as a science and as a result it has both theoretical and practical sides that are related. In discussing the subject is important to cover both of these aspects of the knowledge that comprises this inexact science.

Practical macroeconomics phenomena can be measured and related to the theoretical side, but in general the theories so far submitted are not sufficiently close to the actual society-at-large behavour as to properly explain how it works and to be able to forecast what will happen in future times. Experience is regarded as a good means of estimating what will happen too. For this reason a branch of economics called econometrics has been developed, which is based solely on the past performance of the social system. This performance is expressed mathematically in terms of statistical data and various coefficients for use in suitable time-dependent equations, for determining the behavour of various economics functions and variables. It has failed however, to provide a satisfactory means of telling when a sudden change is due and in general it becomes progressively less accurate in forecasting, as increasing future time intervals are taken.

In considering the theoretical aspects of macroeconomics a number of schools of thought have emerged, none of them being sufficiently complete or precise as to to be able to claim that their version of the science is completely correct. However, progress has been made and it can be said that some of the government policy decision-making as based on the theory has been useful, in that it has helped to both stabilize and advance the progress of the social system. Many alternate theories have been tried, but not all of them have worked properly and some have been adverse to progress. So that for all the profoundity, vitality and need to do the right thing for society-at-large, in fact it is the somewhat more selfish political considerations rather than the ideal theoretical ones that have dominated governmental policy-making.

In considering theoretical macroeconomics the first stage is one of defning terms and trying to set up a clear understanding of what is involved. This is difficult in that many theoretical studies seem to begin without a full statement of the assumptions, axioms and meanings of the terms being used. Thus the resulting (limited) theories, which in fact cover only some of the aspects of the social system-at-large, are not able to be properly joined together, nor do they find application to the whole of the community. Even so, the next stage in the process of developing a theory must then be to establish a suitable model that represents all or part of the social system. It is generally but not always conceded that the whole system is so big and complicated that it is impractical to represent it all, and consequently a smaller partial model is constructed with the unlikely assumption of there being no outside effects occurring during the operation of this model and within the limits of what it represents. Probably because of this, there has been so little agreement about how in theory the system actually works!

The early theories were directed at the aspects of production and consumption of goods so only the householders and producers were included. This is strange because the three factors of production, land, labor and durable capital goods, (and their returns ground-rent, wages and dividends/yield/interest) had already been defined by Adam Smith in 1765. Later theories concerned the effect of trade abroard and the relative effects of prices on the quantities of goods needed for both home and foreign businesses. A theory of money and its circulation was also developed but as can be seen there ideas are difficult as separated theories to become one seamless whole. Also in this discussion it is easy to confuse some of the microeconomics theories, such as those of supply and demand and the associated equilibrium assumptions and anaylses, with the macroeconomics ones which were fewer and less exacting as explained above.85.65.139.173 (talk) 15:43, 4 October 2011 (UTC)

Macroeconomics descended from the once divided fields of business cycle theory and monetary theory. The quantity theory of money was particularly influential prior to World War II. It took many forms including the version based on the work of Irving Fisher:

$M\cdot V=P\cdot Q$

In the typical view of the quantity theory, money velocity (V) and the quantity of goods produced (Q) would be constant, so any increase in money supply (M) would lead to a direct increase in price level (P). The quantity theory of money was a central part of the classical theory of the economy that prevailed in the early twentieth century.

Keynes and his followers

Macroeconomics, at least in its modern form, began with the publication of John Maynard Keynes's General Theory of Employment, Interest and Money. When the Great Depression struck, classical economists had difficulty explaining how goods could go unsold and workers could be left unemployed. In classical theory, prices and wages would drop until the market cleared, and all goods and labor were sold. Keynes offered a new theory of economists that explained why markets might not clear. Keynes presented a new theory of how the economy worked. In Keynes's theory, the quantity theory broke down because people and businesses tend to hold on to their cash in tough economic times, a phenomena he described in terms of liquidity preferences. Keynes explained how the multiplier effect would magnify a small decrease in consumption or investment and cause negative declines throughout the economy. Keynes also noted the role uncertainty and animal spirits can play in the economy.

The generation following Keynes combined the macroeconomics of the General Theory with neoclassical microeconomics to create the neoclassical synthesis. By the 1950s, most economists had accepted the synthesis view of the macroeconomy. Economists like Paul Samuelson, Franco Modigliani, James Tobin, and Robert Solow developed formal Keynesian theories and developed theories of consumption, investment, and money demand that fleshed out the Keynesian framework.

Monetarism

Milton Friedman updated the quantity theory of money to include a role for money demand. He argued that the role of money in the economy was sufficient to explain the Great Depression, and aggregate demand oriented explanations were not necessary. Friedman argued that monetary policy was more effective than fiscal policy; however, Friedman doubted the government has ability to "fine-tune" the economy with monetary policy. He generally favored a policy of steady growth in money supply instead of frequent intervention. Friedman also challenged the Phillips Curve relationship between inflation and unemployment. Friedman and Edmund Phelps (who was not a monetarist) proposed an "augmented" version of the the Phillips Curve that excluded the possibility of a stable, long-run trade off between inflation and unemployment. When the oil shocks of the 1970s created a high unemployment and high inflation, Friedman and Phelps were vindicated. Monetarism was particularly influential in the early 1980s. Monetarism fell out of favor when central banks found it difficult to target money supply instead of interest rates as monetarists recommended. Monetarism also became politically unpopular when the central banks created recessions in order to slow inflation.

New classicals

Another challenge to Keynesianism came from new classical macroeconomics. A central development in new classical thought came when Robert Lucas introduced rational expectations to macroeconomics. Prior to Lucas, economists had generally used adaptive expectations where agents were assumed to look at the recent past to make expectations about the future. Under rational expectations, agents are assumed to be more sophisticated. A consumer will not simply assume a 2% inflation rate because that has been the average the past few years; he will look at current monetary policy and economic conditions to make an informed forecast. When new classical economists introduced rational expectations into their models, they showed that monetary policy could only have a limited impact.

Lucas also made an influential critique of Keynesian empirical models. He argued that forecasting models based on empirical relationships would be unstable. He advocated models based on fundamental economic theory that would, in principle, be more stable as economies changed. Following Lucas's critique, new classical economists, led by Edward C. Prescott and Finn E. Kydland created real business cycle (RBC) models of the macroeconomy. These models were based on combining fundamental equations in neo-classical microeconomics. They produced models that explained recessions and unemployment with changes in technology. The RBC models did not include a role for money to play in the economy. Critics of RBC models argue that money clearly plays an important role in the economy, and the idea that technological regress can explain recent recessions is also implausible. Despite questions about the theory behind RBC models, they have clearly been influential in economic methodology.

New Keynesian response

New Keynesian economists responded to the new classical school by adopting rational expectations and focusing on developing micro-founded models that are immune to the Lucas critique. Stanley Fischer and John B. Taylor produced early work in this area by showing that monetary policy could be effective even in models with rational expectations when contracts locked-in wages for workers. Other new Keynesian economists expanded on this work and demonstrated other cases where inflexible prices and wages led to monetary and fiscal policy having real effects. Like classical models, new classical models had assumed that prices would be able to adjust perfectly and monetary policy would only lead to price changes. New Keynesian models investigated sources of sticky prices and wages, which would not adjust thereby leading monetary policy impact quantities instead of prices.

By the late 1990s, economists had reached a rough consensus. The rigidities of new Keynesian theory were combined with rational expectations and the RBC methodology to produce dynamic stochastic general equilibrium (DSGE) models. The fusion of elements from different schools of thought has been dubbed the new neoclassical synthesis. These models are now used by many central banks and are a core part of contemporary macroeconomics.

Austrian School

Austrian economists generally oppose state intervention in otherwise free markets. Austrian economists view fiscal and monetary policy as primary causes of the "boom-bust" business cycle rather than the cure.

See also

• AP Macroeconomics
• Dynamic stochastic general equilibrium
• Economic development

References

• Blanchard, Olivier (2000), Macroeconomics, Prentice Hall, ISBN 013013306X.
• Blanchard, Olivier (2011). Macroeconomics Updated (5th ed.). Englewood Cliffs: Prentice Hall. ISBN 9780132159869.
• Blaug, Mark (1986), Great Economists before Keynes, Brighton: Wheatsheaf.
• Bouman, John: Principles of Macroeconomics - free fully comprehensive Principles of Microeconomics and Macroeconomics texts. Columbia, Maryland, 2011
• Dwivedi, D.N. (2001). Macroeconomics : theory and policy. New Delhi: Tata McGraw-Hill. ISBN 9780070588417.
• Friedman, Milton (1953), Essays in Positive Economics, London: University of Chicago Press, ISBN 0-226-26403-3.
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• Mishkin, Frederic S. (2004), The Economics of Money, Banking, and Financial Markets, Boston: Addison-Wesley, p. 517
• Snowdon, Brian, and Howard R. Vane, ed. (2002). An Encyclopedia of Macroeconomics, Description & scroll to Contents-preview links.
• Snowdon, Brian (2005), Modern Macroeconomics: Its Origins, Development And Current State, Edward Elgar Publishing, ISBN 1-84376-394-X {{citation}}: Unknown parameter |coauthors= ignored (|author= suggested) (help).
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• Warsh, David (2006), Knowledge and the Wealth of Nations, Norton, ISBN 978-0393059960.