Aggregate supply

Last updated
Aggregate supply curve showing the three ranges: Keynesian, Intermediate, and Classical. In the Classical range, the economy is producing at full employment. Aggregate supply.svg
Aggregate supply curve showing the three ranges: Keynesian, Intermediate, and Classical. In the Classical range, the economy is producing at full employment.

In economics, aggregate supply (AS) or domestic final supply (DFS) is the total supply of goods and services that firms in a national economy plan on selling during a specific time period. It is the total amount of goods and services that firms are willing and able to sell at a given price level in an economy.[ citation needed ]



There are two main reasons why the amount of aggregate output supplied might rise as price level P rises, i.e., why the AS curve is upward sloping:

Aggregate supply is targeted by government "supply-side policies" which are meant to increase productive efficiency and hence national output. Some examples of supply-side policies include education and training, research and development, supporting small/medium entrepreneurs, decreasing business taxes, making labour market reforms to diminish frictions that may hold down output, and investing in infrastructure.

Different scopes

There are generally three alternative degrees of price-level responsiveness of aggregate supply. They are:

  1. Short-run aggregate supply (SRAS) — During the short-run, firms possess one fixed factor of production (usually capital), and some factor input prices are sticky. The quantity of aggregate output supplied is highly sensitive to the price level, as seen in the flat region of the curve in the above diagram.
  2. Long-run aggregate supply (LRAS) — Over the long run, only capital, labour, and technology affect the LRAS in the macroeconomic model because at this point everything in the economy is assumed to be used optimally. In most situations, the LRAS is viewed as static because it shifts the slowest of the three. The LRAS is shown as perfectly vertical, reflecting economists' belief that changes in aggregate demand (AD) have an only temporary change on the economy's total output.
  3. Medium run aggregate supply (MRAS) — As an interim between SRAS and LRAS, the MRAS form slopes upward and reflects when capital, as well as labor usage, can change. More specifically, medium run aggregate supply is like this for three theoretical reasons, namely the Sticky-Wage Theory, the Sticky-Price Theory and the Misperception Theory. The position of the MRAS curve is affected by capital, labour, technology, and wage rate.

In the standard aggregate supply-aggregate demand model, real output (Y) is plotted on the horizontal axis and the price level (P) on the vertical axis. The levels of output and the price level are determined by the intersection of the aggregate supply curve with the downward-sloping aggregate demand curve.

See also

Related Research Articles

Macroeconomics Branch of economics that studies aggregated indicators

Macroeconomics is a branch of economics dealing with the performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes and government spending to regulate an economy’s growth and stability. This includes regional, national, and global economies.


In economics, stagflation or recession-inflation is a situation in which the inflation rate is high, the economic growth rate slows, and unemployment remains steadily high. It presents a dilemma for economic policy, since actions intended to lower inflation may exacerbate unemployment.

Supply and demand Economic model of price determination in microeconomics

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 will equal the quantity supplied, resulting in an economic equilibrium for price and quantity transacted. It forms the theoretical basis of modern economics.

Inflation Rise in price level in an economy over time

In economics, inflation is a general rise in the price level of an economy over a period of time. When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation reflects a reduction in the purchasing power per unit of money – a loss of real value in the medium of exchange and unit of account within the economy. The opposite of inflation is deflation, a sustained decrease in the general price level of goods and services. The common measure of inflation is the inflation rate, the annualised percentage change in a general price index, usually the consumer price index, over time.

IS–LM model macroeconomic model relating interest rates and asset market

The IS–LM model, or Hicks–Hansen model, is a two-dimensional macroeconomic tool that shows the relationship between interest rates and assets market. The intersection of the "investment–saving" (IS) and "liquidity preference–money supply" (LM) curves models "general equilibrium" where supposed simultaneous equilibria occur in both the goods and the asset markets. Yet two equivalent interpretations are possible: first, the IS–LM model explains changes in national income when the price level is fixed in the short-run; second, the IS–LM model shows why an aggregate demand curve can shift. Hence, this tool is sometimes used not only to analyse economic fluctuations but also to suggest potential levels for appropriate stabilisation policies.

Full employment is a situation in which there is no cyclical or deficient-demand unemployment. Full employment does not entail the disappearance of all unemployment, as other kinds of unemployment, namely structural and frictional, may remain. For instance, workers who are "between jobs" for short periods of time as they search for better employment are not counted against full employment, as such unemployment is frictional rather than cyclical. An economy with full employment might also have unemployment or underemployment where part-time workers cannot find jobs appropriate to their skill level, as such unemployment is considered structural rather than cyclical. Full employment marks the point past which expansionary fiscal and/or monetary policy cannot reduce unemployment any further without causing inflation.

New Keynesian economics

New Keynesian economics is a school of macroeconomics that strives to provide microeconomic foundations for Keynesian economics. It developed partly as a response to criticisms of Keynesian macroeconomics by adherents of new classical macroeconomics.

Phillips curve Single-equation economic model relating wages to unemployment

The Phillips curve is a single-equation economic model, named after William Phillips, describing an inverse relationship between rates of unemployment and corresponding rates of rises in wages that result within an economy. Stated simply, decreased unemployment, in an economy will correlate with higher rates of wage rises. Phillips did not himself state there was any relationship between employment and inflation; this notion was a trivial deduction from his statistical findings. Paul Samuelson and Robert Solow made the connection explicit and subsequently Milton Friedman and Edmund Phelps put the theoretical structure in place. In so doing, Friedman was to successfully predict the imminent collapse of Phillips' a-theoretic correlation.

Marginal cost

In economics, marginal cost is the change in the total cost that arises when the quantity produced is incremented by one unit; that is, it is the cost of producing one more unit of a good. Intuitively, marginal cost at each level of production includes the cost of any additional inputs required to produce the next unit. At each level of production and time period being considered, marginal costs include all costs that vary with the level of production, whereas other costs that do not vary with production are fixed and thus have no marginal cost. For example, the marginal cost of producing an automobile will generally include the costs of labor and parts needed for the additional automobile but not the fixed costs of the factory that have already been incurred. In practice, marginal analysis is segregated into short and long-run cases, so that, over the long run, all costs become marginal. Where there are economies of scale, prices set at marginal cost will fail to cover total costs, thus requiring a subsidy. Marginal cost pricing is not a matter of merely lowering the general level of prices with the aid of a subsidy; with or without subsidy it calls for a drastic restructuring of pricing practices, with opportunities for very substantial improvements in efficiency at critical points.

Aggregate demand Total demand for final goods and services in an economy at a given time

In macroeconomics, aggregate demand (AD) or domestic final demand (DFD) is the total demand for final goods and services in an economy at a given time. It is often called effective demand, though at other times this term is distinguished. This is the demand for the gross domestic product of a country. It specifies the amount of goods and services that will be purchased at all possible price levels. Consumer spending, investment, corporate and government expenditure, and net exports make up the aggregate demand.

Nominal rigidity Inertia of prices in economics

Nominal rigidity, also known as price-stickiness or wage-stickiness, is a situation in which a nominal price is resistant to change. Complete nominal rigidity occurs when a price is fixed in nominal terms for a relevant period of time. For example, the price of a particular good might be fixed at $10 per unit for a year. Partial nominal rigidity occurs when a price may vary in nominal terms, but not as much as it would if perfectly flexible. For example, in a regulated market there might be limits to how much a price can change in a given year.

In economics, average cost or unit cost is equal to total cost (TC) divided by the number of units of a good produced :

Neutrality of money is the idea that a change in the stock of money affects only nominal variables in the economy such as prices, wages, and exchange rates, with no effect on real variables, like employment, real GDP, and real consumption. Neutrality of money is an important idea in classical economics and is related to the classical dichotomy. It implies that the central bank does not affect the real economy by creating money. Instead, any increase in the supply of money would be offset by a proportional rise in prices and wages. This assumption underlies some mainstream macroeconomic models. Others like monetarism view money as being neutral only in the long-run.

In economics, a cost curve is a graph of the costs of production as a function of total quantity produced. In a free market economy, productively efficient firms optimize their production process by minimizing cost consistent with each possible level of production, and the result is a cost curve. Profit-maximizing firms use cost curves to decide output quantities. There are various types of cost curves, all related to each other, including total and average cost curves; marginal cost curves, which are equal to the differential of the total cost curves; and variable cost curves. Some are applicable to the short run, others to the long run.

Mundell–Fleming model Economic model

The Mundell–Fleming model, also known as the IS-LM-BoP model, is an economic model first set forth (independently) by Robert Mundell and Marcus Fleming. The model is an extension of the IS–LM model. Whereas the traditional IS-LM model deals with economy under autarky, the Mundell–Fleming model describes a small open economy.

In economics the long-run is a theoretical concept in which all markets are in equilibrium, and all prices and quantities have fully adjusted and are in equilibrium. The long-run contrasts with the short-run, in which there are some constraints and markets are not fully in equilibrium.

AD–AS model macroeconomic model relating aggregate demand and supply

The AD–AS or aggregate demand–aggregate supply model is a macroeconomic model that explains price level and output through the relationship of aggregate demand and aggregate supply.

Keynesian cross

The Keynesian cross diagram is a formulation of the central ideas in Keynes' General Theory. It first appeared as a central component of macroeconomic theory as it was taught by Paul Samuelson in his textbook, Economics: An Introductory Analysis. The Keynesian Cross plots aggregate income and planned total spending or aggregate expenditure.

Factor market

In economics, a factor market is a market where factors of production are bought and sold. Factor market allocates factors of production, including land, labour and capital, and distribute income to the owners of productive resources, such as wages, rents, etc.

In economics, factor payments are the income people receive for supplying the factors of production: land, labor, capital or entrepreneurship.