Modern Economic Thought

After Keynes, economics did not settle into a single, final school of thought — instead, several strands developed, often in reaction to one another, and together they make up what is broadly called modern economic thought.

The neo-classical synthesis, developed by economists such as Paul Samuelson from the 1940s onward, attempted to combine Keynesian short-run demand management (useful for stabilising the economy during recessions) with the older classical/neo-classical framework of markets and prices (useful for explaining how resources are allocated efficiently in the long run) — treating the two as complementary rather than rival approaches, each suited to a different time horizon.

Monetarism, associated above all with the American economist Milton Friedman, pushed back against the Keynesian emphasis on fiscal policy and argued instead that the money supply is the dominant influence on national income, prices and inflation in the long run, and that governments should focus on steady, predictable growth in the money supply rather than actively fine-tuning the economy through spending and taxation.

Welfare economics, developed early on by A. C. Pigou (a student of Marshall) and extended by many later economists, studies how efficiently and how fairly an economy's resources serve overall social well-being — going beyond just measuring total output to ask questions about its distribution, and providing the theoretical basis for government intervention (such as taxes and subsidies) to correct situations where private markets fail to account for costs or benefits imposed on third parties. …