Keynesian Versus Classical Long-run AS
- Long run aggregate supply (LRAS) is influenced by a change in the productive capacity of the economy
- Productive capacity is changed by changes to the quantity or quality of the factors of production
- Economists have two opposing views on how LRAS works in an economy
- The original view is called the classical view
- The insights developed by John Meynard Keynes in 1936 are called the Keynesian view
The Classical LRAS View
- The classical view believes that the LRAS is perfectly inelastic (vertical) at a point of full employment of all available resources
- This point corresponds to the maximum possible output on a production possibilities frontier (PPF)
- This point corresponds to the maximum possible output on a production possibilities frontier (PPF)
- The classical view believes that in the long-run an economy will always return to this full employment level of output
- There may be short-run output gaps in the economy
- During extreme periods of economic growth there can be an inflationary gap that develops
- In the long run this will self-correct and return to the long-run level of output, but at a higher average price level
- During slowdowns or recessions there can be a recessionary gap that develops
- In the long-run this will self-correct and return to the long-run level of output, but at a lower average price level
- During extreme periods of economic growth there can be an inflationary gap that develops
A diagram that shows the Classical View of long-run aggregate supply (LRAS) with a vertical aggregate supply curve at the full employment level of output (YFE)
Diagram Analysis
- Using all available factors of production, the long-term output of this economy (LRAS) occurs at YFE
- The economy is initially in equilibrium at the intersection of AD1 and LRAS (P1, YFE)
- A slowdown reduces output from AD1→AD2 and creates a short term recessionary gap
- This self corrects in the long term and returns the economy to the long-run equilibrium at the intersection of AD2 and LRAS (P2, YFE)
The Keynesian LRAS View
- Keynes believed that the long-run aggregate supply curve (LRAS) was more L shaped
- Supply is elastic at lower levels of output as there is a lot of spare production capacity in the economy
- Struggling firms will increase output without raising prices
- Supply is perfectly inelastic (vertical) at a point of full employment (YFE) of all available resources
- The closer the economy gets to this point the more price inflation will occur as firms compete for scarce resources
- The closer the economy gets to this point the more price inflation will occur as firms compete for scarce resources
- Supply is elastic at lower levels of output as there is a lot of spare production capacity in the economy
- The Keynesian view believes that an economy will not always self-correct and return to the full employment level of output (YFE)
- It can get stuck at an equilibrium well below the full employment level of output e.g. Great Depression
- It can get stuck at an equilibrium well below the full employment level of output e.g. Great Depression
- The Keynesian view believes that there is role for the government to increase its expenditure so as to shift aggregate demand and change the negative 'animal spirits' in the economy
A diagram that shows the Keynesian View of long-run aggregate supply (LRAS) with a vertical aggregate supply curve at the full employment level of output (YFE) becoming more elastic at lower levels of output
Diagram Analysis
- Using all available factors of production, the long-term output of this economy (LRAS) occurs at YFE
- The economy is initially in equilibrium at the intersection of AD1 and LRAS (P1, YFE)
- A slowdown reduces output from AD1→AD2 and creates a recessionary gap Y1-YFE
- The economy may reach a point where average prices stop falling (P2), but output continues to fall
- This economy may not self-correct to YFE for years
- The low output leads to high unemployment and low confidence in the economy
- This stops further investment and further reduces consumption
- This stops further investment and further reduces consumption
- Keynes argued that this was where governments needed to intervene with significant expenditure e.g. Roosevelt's New Deal; response to financial crisis of 2008