Lably
Skip to content

Neoclassical synthesis

Postwar academic movement in economics

  • 17 min read
  • 8 chapters

Related on Lably

Through Economics, Macroeconomics and John Maynard Keynes

The neoclassical synthesis is a macroeconomic theory that emerged in the mid-20th century, combining the ideas of neoclassical economics with Keynesian economics. The synthesis was an attempt to reconcile the apparent differences between the two schools of thought and create a more comprehensive theory of macroeconomics.

It was formulated most notably by John Hicks (1937), Franco Modigliani (1944), and Paul Samuelson (1948), who dominated economics in the post-war period and formed the mainstream of macroeconomic thought in the 1950s, 60s, and 70s.

The Keynesian school of economics had gained widespread acceptance during the Great Depression, as governments used deficit spending and monetary policy to stimulate economic activity and reduce unemployment. However, neoclassical economists argued that Keynesian policies could lead to inflation and other economic problems. They believed that markets would eventually adjust to restore equilibrium, and that government intervention could disrupt this process.

In the 1950s and 1960s, economists like Paul Samuelson and Robert Solow developed the neoclassical synthesis, which attempted to reconcile these two schools of thought. The neoclassical synthesis emphasized the role of market forces in the economy, while also acknowledging the need for government intervention in certain circumstances. According to the neoclassical synthesis, the economy operates according to the principles of neoclassical economics in the long run, but in the short run, Keynesian policies can be effective in stimulating economic growth and reducing unemployment. The synthesis also emphasized the importance of monetary policy in controlling inflation and maintaining economic stability. Overall, the neoclassical synthesis was a significant development in the field of macroeconomics, as it brought together two previously competing schools of thought and created a more comprehensive theory of the economy.

A series of developments occurred that shook the neoclassical synthesis in the 1970s as the advent of stagflation and the work of monetarists like Milton Friedman cast doubt on the synthesis' conceptions of monetary theory. The conditions of the period proved the impossibility of maintaining sustainable growth and low level of inflation via the measures suggested by the school. The result would be a series of new ideas to bring tools to macroeconomic analysis that would be capable of explaining the economic events of the 1970s. Subsequent new Keynesian and new classical economists strived to provide macroeconomics with microeconomic foundations, incorporating traditionally Keynesian and neoclassical characteristics respectively. These schools eventually came to form a "new neoclassical synthesis", analogous to the neoclassical one, that currently underpins the mainstream of macroeconomic theory.

Emergence of the neoclassical synthesis

Several of these accounts, taken from Peter Howitt, N. Gregory Mankiw, and Michael Woodford's writings, are presented here for the reader's consideration:

It seemed logical to regard Keynesian theory as relating to short-run fluctuations and general equilibrium theory as applying to long-run difficulties where adjustment problems could be safely neglected because wages were widely believed to be less than totally flexible in the short term. The "neoclassical synthesis" is the name given to this perspective. Since macroeconomics emerged as a distinct field of study, how to reconcile these two economic visions—one founded on Adam Smith's invisible hand and Alfred Marshall's supply and demand curves, the other on Keynes's analysis of an economy suffering from insufficient aggregate demand—has been a profound, nagging question. The 'neoclassical-Keynesian synthesis,' as it is frequently referred to, was supposed to have reconciled these ideas by early Keynesians like Samuelson, Modigliani, and Tobin. These economists thought that while the Keynesian description of the invisible hand may paralyze it in the short run was true, the classical theory of Smith and Marshall was correct in the long run.

After the Great Depression, and particularly in America, the "neoclassical synthesis" became the dominant viewpoint. The neoclassical synthesis suggested that both the Keynesian theory and the neoclassical general equilibrium theory could be seen as true, albeit incomplete, descriptions of economic reality. It was created, among others, in the first decade following Keynes' writing, by John R. Hicks and Paul A. Samuelson.

It was maintained that the traditional theory of general competitive equilibrium, once wages and prices had sufficiently had time to adjust to clear markets, would accurately describe the determination of prices and quantities in the long run. At the same time, it was suggested that the Keynesian model could explain the short-term consequences of both economic disruptions and policy changes, before prices and wages had much time to react. The 'neoclassical synthesis' allowed postwar Keynesians to maintain that there was no fundamental incompatibility between microeconomic and macroeconomic theory. The specifics of how one got from the Keynesian short run to the "classical" long run were not really worked out.

All of these quotes point to the same conclusion: the concern of the neoclassical synthesis is the relationship between the short and long periods, the first of which is the area of study of Keynesian theory because it is characterized by stickiness and market non-clearing, and the latter by flexibility and market clearing. Here, in contrast to Samuelson's statements, the focus is more on theoretical advancements than on a consensus regarding policy.

Macroeconomics had significant advancements between 1940 and 1970; as a result, Blanchard refers to this time as the "golden age" of macroeconomics. Major strides have also been achieved in the analysis of the three behavior functions—consumption, investment, and money demand—that were the basis for the IS-LM model. In an additional effort to quantify the hypotheses derived from theoretical models, macro-econometric models were created. In addition, the Solow neoclassical economic growth model was created at the same time to explore the factors that influence economic growth.

Sign in to keep reading

7 more chapters are free with a Lably account.

More in Economics