Monetary Policy
What is monetary policy?
It is the control of the money supply and interest rates by a countries central bank to influence the economy.
How monetary policy works in normal times?
Main tool; Changing the policy interest rate
Expansionary (Loosening) Monetary policy
• central banks cut interest rates
• This makes borrowing cheaper, encouraging consumer spending and investment
• Also lowers the return on domestic assets = currency depreciates = exports become cheaper
• All this increases aggregate demand
GDP increases
Contractionary (tightening) Monetray policy;
Central banks raises interest rates
Slows borrowing and spending
Helps cool inflation
The MPC story; transmission Mechanism
MPC is how much people spend out of each extra dollar they get
Monetary policy is more powerful when MPC is high - as people respond quickly to rate cuts by increasing consumption
But there’s a catch;
• If households are already in debt, or uncertain about the future, they may save instead of spend.
• That weakens the effect of rate cuts
What happens when interest rate hit Zero?
After major shocks, central banks cut interest rates to near 0%.
But you can’t go much lower than (zero lower bound)
At this point, traditionally monetary policy loses power
So central banks turn to unconventional tools- that’s where QE comes in
Quantitative easing
What is QE?
QE = Large scale asset purchases by the central bank
Central banks creates digital money to buy;
• Government bonds
• Mortgage backed securities
• Corporate bonds
Main goal
• Lower long term interest rate (short term are already near 0)
• Increase asset prices
• Stimulate credit and spending
• Prevent deflation
Transmission mechanism
1. CB buys bond - bond prices increase and yields decrease
2. Lower yields means cheaper borrowing for firms and households
3. Investors move to riskier assets (stocks, corporate bonds) - wealth effect
4. Higher asset prices make people feel wealthier - consumption increases
5. Increased liquidity in banking systems - more lending
QT - Quantitative tightening
After years of QE, central banks built up huge balance sheets.
QT = process of shrinking the central banks balance sheet
How?
• Stop reinvesting when bonds mature
• Or actively sell assets
Goals of QT
• Remove excess liquidity
• Allow interest to rise naturally
• Reduce inflationary pressure
• Qt is a form of monetary tightening but
• It’s slower and more passive than rate hikes
• It can still push up long term interest rates
🎯 Why QE Was Used (and Controversial)
🛠 QE was used because:
Interest rates were at zero
Inflation was too low
Economies needed stimulus
😬 But it's controversial:
May inflate asset bubbles
Widen inequality (rich benefit more from rising asset prices)
Hard to unwind (markets get addicted to cheap money)
May weaken currency, creating global tensions
🧾 Summary Table
Tool Normal Monetary Policy QE QT
Purpose Control short-term rates Stimulate at ZLB Normalize after QE
Method Adjust policy interest rate Buy assets (bonds) Let assets roll off or sell them
Effect Affects borrowing/lending Lowers long-term rates, boosts spending Tightens liquidity
Used in “Normal” times Recessions, deflationary periods Post-crisis, hig