- The monetarist/new classical and Keynesian models come from 2 different economics schools of thought.
- Understanding their different assumptions and implications is crucial for analysing economic fluctuations and policy responses.
The monetarist/new classical model
Assumptions
- Flexible wages and prices:
- Wages and prices adjust to restore equilibrium.
- If AD falls, a decrease in price level causes wages to decrease, reducing production costs and increasing AS.
- Vertical long-run aggregate supply (LRAS) curve:
- The LRAS curve is vertical at the full employment level of output (potential output).
- Potential output is determined by the production possibilities of the economy, not the price level.
- Full employment as the norm:
- The economy naturally gravitates towards full employment.
- Any deviation is temporary and corrected by market forces.
- Need for minimal government intervention:
- Since the economy is self-regulating, government intervention is unnecessary, and it may be harmful if it alters the market self-correction mechanism.
- Policies should focus on long-term growth by expanding the production possibilities (supply-side policies).
The monetarist/new classical model emphasises the economy’s ability to self-correct through flexible wages and resource prices, assuming full employment is the natural state of the economy.
Implications
- Temporary output gaps:
- Inflationary or recessionary gaps are short-lived.
- Market forces restore equilibrium at full-employment in the long run.
- Ineffectiveness of demand-side policies:
- Fiscal and monetary policies (demand-side policies) aim to shift the AD curve.
- However, in the long run, shifts in AD only affect the price level, not potential output.
- Therefore, increasing AD beyond its full employment equilibrium only leads to inflation, not to increasing real output.
- This makes demand-side policies ineffective in the long-run.
- Focus on supply-side policies
- Long-term growth depends on improving the production possibilities of the economy.
- Policies should focus on the supply-side of the economy, driving growth in production possibilities.
Monetarist model: automatic self-correction
Who: Technology Industry
Where: United States
When: 2022-2023
What Happened: Mass layoffs occurred across major tech companies following a period of cost-push inflation.
Why: Rising production costs, particularly higher labor costs, led companies to reassess their expenses and reduce their workforce to maintain profitability.
How:
- Cost-push inflation (cause by a leftward shift in SRAS) occurs when the costs of production increase (wages, raw materials...).
- In response, firms in the technology sector made workers redundant to reduce costs.
- The loss of income for these workers reduced aggregate demand (AD) by reducing consumer spending (C), which helped counter the inflationary pressures.
- This adjustment aligns with the monetarist belief that profit-maximizing firms drive market self-correction.
So?:
- The market corrected itself without requiring government intervention, consistent with the monetarist model.
- The reduction in aggregate demand helped stabilise price levels over time, as the economy moved toward long-run equilibrium.
- This demonstrates the self-correcting mechanism of markets, where price and demand adjustments occur naturally through profit-driven decisions by firms, reflecting minimal government interference in the economy.
Monetarist model: Aggregate Demand increases are always inflationary
When: 2021-22
Where: United States
What: Post-COVID-19 economic recovery led to significant demand-pull inflation.
Why:
- During the COVID-19 pandemic, lockdowns and restrictions significantly limited spending opportunities, leading to increased household savings.
- Governments introduced stimulus measures (e.g., direct payments, unemployment benefits) to revive economic activity during the downturn.
- Once restrictions were lifted, pent-up demand and surplus savings caused a sharp rise in consumption, increasing aggregate demand (AD).
How:
- Relaxation of restrictions: as people returned to normal activities, they began spending saved income on goods and services.
- Government stimulus: fiscal measures boosted consumer purchasing power, further amplifying demand.
- Aggregate Demand surge: these factors combined to shift the AD curve to the right, leading to an increase in the price level and inflation.
So?:
- This case demonstrates how a sharp increase in AD, even from a deflationary gap (e.g., annual growth rate of -2% in 2020), can trigger inflation.
- It supports the monetarist principle that increases in AD are inherently inflationary when the economy nears or surpasses its productive capacity.
- While this AD increase contributed to economic recovery, it also led to inflationary pressures, highlighting the trade-off between growth and price stability in a demand-driven recovery.
The Keynesian model
Assumptions
- Wages and prices are sticky:
- Wages and prices do not adjust easily, especially downward.
- This rigidity can prolong recessionary gaps.
- Three-part aggregate supply curve:
- Horizontal section: at low output levels, there is significant spare capacity, and output can increase without raising prices.
- Upward-sloping section: as output approaches full employment, scarce resources cause prices to rise.
- Vertical section: at full employment, output cannot increase further, and any increase in AD leads to inflation (rise in price level).
- Prolonged recessionary gaps:
- The economy can remain below full employment for extended periods.
- Market forces alone are insufficient to restore equilibrium at full-employment.
- Active government intervention:
- Fiscal and monetary policies are necessary to close output gaps.
- Government spending (G) can boost AD and reduce unemployment.
The Keynesian model highlights the economy’s inability to self-correct during recessions due to wage and resource price rigidity, advocating for government intervention to restore equilibrium at full-employment.
Implications
- Persistent recessionary gaps
- Without intervention, high unemployment and low output can persist.
- Wages are “sticky” downward, preventing the natural adjustment of AS.
- Effectiveness of demand-side policies
- Expansionary fiscal and monetary policies can increase AD and close recessionary gaps.
- Government spending (G) is particularly effective when the economy is below full employment.
- Inflationary pressures at full employment
- Increasing AD beyond full employment leads to inflation without increasing output.
- Policymakers must balance stimulating growth and controlling inflation.
Keynesian model: persistence of deflationary gaps
When: 2008
Where: Global, with significant impacts on the United States
What: The 2008 financial crisis (Global Financial Crisis) marked a severe global economic downturn triggered by the collapse of the U.S. housing market and a subsequent banking crisis.
Why:
- The crisis began with the bursting of the U.S. housing bubble, leading to a wave of mortgage defaults.
- This destabilized major financial institutions, froze credit markets, and caused widespread financial instability.
- The resulting drop in consumer and business confidence caused a sharp decline in spending and investment, creating a global recession.
How:
- Deflationary Gap: The crisis led to significant underutilization of resources, high unemployment, and reduced economic activity, shifting the economy far below its potential output.
- Horizontal AS Curve: From a Keynesian perspective, the global economy operated on the flat portion of the aggregate supply curve, where increases in aggregate demand (AD) did not trigger inflation.
- Policy Measures: Efforts to stimulate AD through monetary policy, such as lowering interest rates, were insufficient on their own to close the gap. Fiscal policy interventions were necessary to stimulate demand and address widespread unemployment.
So?
- The 2008 financial crisis highlights how deflationary gaps can persist over long periods, even with attempts to increase AD.
- It demonstrates that in severe recessions, increases in AD do not always result in inflation, as underutilized resources and excess capacity absorb the demand.
- The crisis underscores the importance of Keynesian principles in addressing economic stagnation, emphasizing the need for coordinated fiscal policy alongside monetary measures to restore full employment and economic stability.
Summary: comparing the two models
| Aspect | Monetarist/New Classical Model | Keynesian Model |
|---|---|---|
| Wage and Price Flexibility | Flexible, allowing quick adjustments | Sticky, especially downward |
| Long-Run Aggregate Supply | Vertical at full employment | Three-part curve (horizontal, upward-sloping, vertical) |
| Role of Government | Minimal intervention | Active intervention needed |
| Output Gaps | Temporary and self-correcting | Can be prolonged without intervention |
| Policy Effectiveness | Demand-side policies ineffective in the long run | Demand-side policies effective in closing gaps |
Can you explain the key differences between the monetarist/new classical and Keynesian models? How do these differences impact their views on government intervention?


