macroeconomics Macroeconomics is a branch of economics that deals with the performance, structure, behavior, and decision-making of an economy as a whole. This includes regional, national, and global economies. Macroeconomists study topics such as output (econ ...

, the classical dichotomy is the idea, attributed to classical and pre-

Keynesian Keynesian economics ( ; sometimes Keynesianism, named after British economist John Maynard Keynes) are the various macroeconomic theories and models of how aggregate demand (total spending in the economy) strongly influences economic output an ...

economics, that real and nominal variables can be analyzed separately. To be precise, an economy exhibits the classical dichotomy if real variables such as output and

real interest rate The real interest rate is the rate of interest an investor, saver or lender receives (or expects to receive) after allowing for inflation. It can be described more formally by the Fisher equation, which states that the real interest rate is appro ...

s can be completely analyzed without considering what is happening to their nominal counterparts, the money value of output and the interest rate. In particular, this means that

real GDP Real gross domestic product (real GDP) is a macroeconomic measure of the value of economic output adjusted for price changes (i.e. inflation or deflation). This adjustment transforms the money-value measure, nominal GDP, into an index for quantit ...

and other real variables can be determined without knowing the level of the nominal

money supply In macroeconomics, money supply (or money stock) refers to the total volume of money held by the public at a particular point in time. There are several ways to define "money", but standard measures usually include currency in circulation (i ...

or the rate of

inflation In economics, inflation is an increase in the average price of goods and services in terms of money. This increase is measured using a price index, typically a consumer price index (CPI). When the general price level rises, each unit of curre ...

. An economy exhibits the classical dichotomy if money is neutral, affecting only the price level, not real variables. As such, if the classical dichotomy holds, money only affects absolute rather than the relative prices between goods. The classical dichotomy was integral to the thinking of some pre-Keynesian economists (" money as a veil") as a long-run proposition and is found today in new classical theories of macroeconomics. In new classical macroeconomics there is a short-run Phillips curve which can shift vertically according to the rational expectations being reviewed continuously. In the strict sense, money is not neutral in the short-run, that is, classical dichotomy does not hold, since agents tend to respond to changes in prices and in the quantity of money through changing their supply decisions. However, money should be neutral in the long run, and the classical dichotomy should be restored in the long-run, since there was no relationship between prices and real macroeconomic performance at the data level. This view has serious economic policy consequences. In the long-run, owing to the dichotomy, money is not assumed to be an effective instrument in controlling macroeconomic performance, while in the short-run there is a trade-off between prices and output (or unemployment), but, owing to rational expectations, government cannot exploit it in order to build a systematic countercyclical economic policy.

Keynesians Keynesian economics ( ; sometimes Keynesianism, named after British economist John Maynard Keynes) are the various macroeconomic theories and models of how aggregate demand (total spending in the economy) strongly influences economic output an ...

and

monetarists Monetarism is a school of thought in monetary economics that emphasizes the role of policy-makers in controlling the amount of money in circulation. It gained prominence in the 1970s, but was mostly abandoned as a direct guidance to monetar ...

reject the classical dichotomy, because they argue that prices are sticky. That is, they think prices fail to adjust in the

short run 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 a ...

, so that an increase in the money supply raises

aggregate demand In economics, 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 ...

and thus alters real macroeconomic variables. Post-Keynesians reject the classic dichotomy as well, for different reasons, emphasizing the role of banks in creating money, as in

monetary circuit theory Monetary circuit theory is a heterodox theory of monetary economics, particularly money creation, often associated with the post-Keynesian school. It holds that money is created endogenously by the banking sector, rather than exogenously by cen ...

References

Further reading