Inflation Notes

Inflation

The Neutrality of Money

• Real outcomes in the economy are not affected by aggregate price levels (i.e., nominal variables).
• This is a concept from the Classical school of thought, not Keynesian.
• In the Aggregate Demand-Aggregate Supply (AD-AS) model, after an increase in the money supply, the long-run (LR) effect concerns the neutrality of money.
• Quantity Theory of Money (QTM): The value of money is determined by the money supply.
• Quantity Equation: $M \cdot V = P \cdot Y$, where:
  • $M$ = Money supply
  • $V$ = Velocity of money
  • $P$ = Price level
  • $Y$ = Real GDP
• Velocity of money: The number of times the entire money supply is exchanged in a given period.

The Neutrality of Money (Continued)

• QTM (continued):
  • Assumptions:
    • Velocity ($V$) is usually relatively constant.
    • Money is neutral, so $M$ cannot affect $Y$.
  • Conclusion: $\Delta M = \Delta P$

Velocity of Money: Example Scenarios

• Using the quantity equation $M \cdot V = P \cdot Y$ to fill in the blanks:
  • Scenario 1:
    • Price level ($P$) = $1
    • Real output ($Y$) = $10,000
    • Money supply ($M$) = $5,000
    • $5000 \cdot V = 1 \cdot 10000$
    • Velocity of money ($V$) = 2
  • Scenario 2:
    • Price level ($P$) = $1
    • Real output ($Y$) = $15,000
    • Velocity of money ($V$) = 3
    • $M \cdot 3 = 1 \cdot 15000$
    • Money supply ($M$) = $5,000
  • Scenario 3:
    • Price level ($P$) = $2
    • Real output ($Y$) = $25,000
    • Money supply ($M$) = $10,000
    • $10000 \cdot V = 2 \cdot 25000$
    • Velocity of money ($V$) = 5
  • Scenario 4:
    • Money supply ($M$) = $8,000
    • Real output ($Y$) = $32,000
    • $8000 \cdot V = P \cdot 32000$
    • If $P=1$, then $V = 4$

Costs of Inflation

• Why is inflation bad?
  • Menu costs: The costs associated with businesses changing prices (e.g., reprinting menus).
  • Shoe-leather costs: The costs associated with reduced real money holdings and the effort to minimize them (e.g., more frequent trips to the bank).
  • Tax distortions: Inflation can distort the tax system, leading to unintended changes in tax liabilities.
  • Arbitrary wealth redistribution: Unexpected inflation can redistribute wealth between borrowers and lenders.
• Fisher Effect: $i = r + \pi$, where:
  • $i$ = Nominal interest rate
  • $r$ = Real interest rate
  • $\pi$ = Inflation rate