Perhaps more so than any other social science, economics has been divided into many different schools of thought, supporting different methodologies and ideologies. This is an incomplete summary of some of the major schools of thought in economics outlining their methodological differences.
The neo classical school of thought began with the marginalist revolution in the late 19th century with the works of Alfred Marshall and Léon Walras. After being displaced by Keynesianism, it resurfaced with the works of Milton Friedman in the 1970's. Neo Classicals emphasize:
Neo classicals tend to view government intervention as unnecessary and possibly counterproductive, due to the perceived self-correcting nature of markets in the long run.
The New Keynesian school developed from the synthesis of neo-classical microeconomics with a Hicksian interpretation of Keynes. It is arguably now the dominant school of economics, being taught in most major universities. New Keynesian economics is similar, methodologically, to modern neoclassical economics with the exception that it acknowledges the possibility for market disequilibrium in the short run, meaning government intervention may be appropriate in times of crisis.
The Austrian school developed from the work of Austrian marginalist thinkers such as Carl Menger, Eugen von Böhm-Bawerk, Ludwig von Mises, and Friedrich Hayek, as well as American economist Murray Rothbard. Methodologically, Austrian economists emphasize:
Austrians tend to favour deregulation and a minimal role for the State, promoting, for example, competing currencies.
Post Keynesian economics developed from the theories of John Maynard Keynes and his colleagues at Cambridge - Roy Harrod, Richard Kahn, Joan Robinson, Nicholas Kaldor, Michal Kalecki and Pierro Sraffa.[1] Post Keynesians emphasize:
Post Keynesians tend to favour strong government intervention within the context of a capitalist system.