Macroeconomic Policy Instruments & Aggregate Demand

Federal Reserve & Monetary Policy

• Central bank’s overarching goal: achieve macro-economic targets (stable prices, full employment, growth).
• Policy instrument that actually moves the Aggregate Demand (AD) curve = the money supply (M).
  • The Fed does not directly set AD; it manipulates $M$ which moves interest rates, which in turn influences AD.
• What the Fed directly controls:
  • Quantity of money in circulation (money supply).
  • Indirectly, the short-term interest rate through targeting.
  • Influences inflation and economic growth by these channels.

Open-Market Operations & The Federal Funds Rate (FFR)

• Open-Market Operations (OMO):
  • Buying & selling U.S. Treasury securities.
  • Primary tool for expanding or contracting $M$.
• Federal Funds Rate:
  • Overnight interest rate banks charge one another for reserves.
  • News headlines reference “the Fed raises/lowers rates” → they mean the target FFR.
  • Changes in FFR ripple to all other market rates → household & firm borrowing costs.
• Chain of causation for AD shift (contractionary example):
  • Fed sells bonds → $M$ ↓ → FFR ↑ → market rates ↑ → consumption & investment ↓ → quantity of goods/services demanded at every $P$ ↓ → AD shifts left.

Fiscal Policy: Overview

• Controlled by elected government (President & Congress), not the Fed.
• Two policy levers:
  1. Government Purchases/Spending (G).
  2. Taxes (T).
• Two directional stances:
  • Expansionary FP: $G↑$ and/or $T↓$ → AD shifts right.
  • Contractionary FP: $G↓$ and/or $T↑$ → fights inflation → AD shifts left.

Two Fiscal-Policy Transmission Effects on AD

1. Multiplier Effect

• Government spending (or tax cut) creates repeated rounds of income & expenditure.
• Classroom illustration:
  • Gov’t buys $20\text{ Bn}$ planes from Boeing → Boeing revenue ↑ $20\text{ Bn}$.
  • Boeing distributes to workers (wages) & owners (dividends) → disposable income ↑.
  • Recipients spend at other firms → those firms raise wages/dividends, etc.
  • Each round multiplies the initial injection → AD curve shifts right more than the original $\Delta G$.
• Size of the shift governed by the Spending Multiplier (k).

2. Crowding-Out Effect

• When government deficit-spends it must borrow in the loanable-funds market.
  • Competes with private borrowers (firms & households).
• Government demand for funds drives interest rates up, causing:
  • Private investment spending ↓.
  • Potential fall in income & AD (partial or full offset of the initial expansion).
• Net result: Actual AD shift can be smaller than the shift predicted by the multiplier alone; in extreme cases could negate it.

Marginal Propensity to Consume (MPC) & Spending Multiplier

• Definition: $MPC = \dfrac{\Delta C}{\Delta Y}$
  • Fraction of an extra dollar of income that households spend (not save).
• Spending Multiplier Formula: $k = \dfrac{1}{1 - MPC}$
  • Directly links $MPC$ to total change in AD.
• Relationship: Higher MPC ⇒ higher k.
• Numerical examples:
  • $MPC = 0.5 \;\Rightarrow\; k = 2$
  • $MPC = 0.75 \;\Rightarrow\; k = 4$
  • $MPC = 0.9 \;\Rightarrow\; k = 10$
• Boeing case: $MPC = 0.8$, income ↑ $100$ → consumption ↑ $80$.

Changes in Taxes & Household Perceptions

• Permanent tax cut → large, confident rise in disposable income → bigger AD rightward shift.
• Temporary tax cut → households expect future taxes → smaller spending response → modest AD shift.
• Current context given: expiration of payroll-tax cuts would lower disposable income → AD falls → potential stagnation.

Automatic Stabilizers

• Built-in fiscal/monetary mechanisms that automatically counteract business-cycle swings without new legislation.

Fiscal Automatic Stabilizers

• Progressive tax system: incomes fall in recession → tax liabilities fall automatically → cushions disposable income.
• Government transfer programs: unemployment insurance, welfare, SNAP, etc. → payouts rise in downturn → supports consumption.

Monetary-Side (interest-rate) Stabilizer Concept

• In a slump, central bank can lower policy rates → encourages borrowing & investment → AD ↑.
• Low rates make capital projects & homes more affordable, stimulating the economy.

Quick Reference: Direction of Key Policies on AD

• Fed sells bonds / $M↓$ / rates ↑ → AD left.
• Fed buys bonds / $M↑$ / rates ↓ → AD right.
• $G↑$ or $T↓$ → Multiplier → AD right (offset by potential crowd-out).
• $G↓$ or $T↑$ → AD left (fights inflation).

Equations & Formulas to Memorize

• $MPC = \dfrac{\Delta C}{\Delta Y}$
• $k = \dfrac{1}{1 - MPC}$ (simple spending multiplier).

Ethical & Practical Implications Mentioned

• Too much deficit borrowing may sacrifice private sector investment (crowding out).
• Tax-policy design (permanent vs temporary) changes behavior, influencing overall economic growth.
• Balance required between fighting inflation (monetary tightening) and avoiding excessive drag on growth.

Connections to Earlier Principles / Real-World Relevance

• Loanable-Funds Market: crowding-out story ties directly to supply-demand for savings.
• IS-LM or AD-AS frameworks: lecture’s AD shifts correspond to movements along aggregate-supply curves in full models.
• Current news on Fed meetings & FFR offers live examples of concepts.