What is Monetary Policy?¶
Monetary policy refers to the actions taken by a country’s central bank to control the money supply and interest rates to achieve macroeconomic objectives like:
- Price stability (controlling inflation)
- Full employment
- Economic growth
- Financial stability
Key Central Banks¶
| Central Bank | Region | Key Rate |
|---|---|---|
| Federal Reserve (Fed) | United States | Federal Funds Rate |
| ECB | Eurozone | Main Refinancing Rate |
| Bank of England | United Kingdom | Bank Rate |
| Bank of Japan | Japan | Policy Balance Rate |
| PBoC | China | Loan Prime Rate |
The Interest Rate Mechanism¶
How Rate Changes Affect the Economy¶
Rate Increase (Hawkish):
- Borrowing becomes expensive
- Consumers spend less
- Businesses invest less
- Currency strengthens
- Inflation decreases
Rate Decrease (Dovish):
- Borrowing becomes cheap
- Consumers spend more
- Businesses invest more
- Currency weakens
- Inflation increases
The Taylor Rule¶
A guideline for how central banks should set interest rates:
$$i = r^ + \pi + 0.5(\pi - \pi^) + 0.5(y - y^*)$$
Where:
- i = nominal interest rate
- r = real equilibrium rate (~2%)
- π = current inflation
- π = target inflation
- y - y*** = output gap
Quantitative Easing (QE)¶
When interest rates hit zero (the zero lower bound), central banks can still stimulate the economy through QE:
- Central bank creates new money electronically
- Uses it to buy government bonds and other assets
- This lowers long-term interest rates
- Makes borrowing cheaper for everyone
- Encourages spending and investment
QE Timeline (Fed)¶
- QE1 (2008-2010): Response to financial crisis, ~$1.75T
- QE2 (2010-2011): Additional stimulus, ~$600B
- QE3 (2012-2014): Open-ended purchases, ~$1.6T
- COVID QE (2020-2022): Massive response, ~$4.6T
Inflation Dynamics¶
The Phillips Curve¶
There’s historically an inverse relationship between unemployment and inflation:
- Low unemployment → workers demand higher wages → prices rise → inflation
- High unemployment → less wage pressure → prices stable → low inflation
Types of Inflation¶
| Type | Cause | Example |
|---|---|---|
| Demand-pull | Too much demand | Post-COVID spending surge |
| Cost-push | Rising production costs | Oil price shocks |
| Built-in | Wage-price spiral | 1970s stagflation |
Impact on Financial Markets¶
Bond Markets¶
- Rate increase → bond prices fall (inverse relationship)
- Rate decrease → bond prices rise
- Duration risk: longer-term bonds are more sensitive
Stock Markets¶
- Dovish policy → stocks tend to rally (cheap money)
- Hawkish policy → stocks tend to fall (expensive money)
- But it’s never this simple in practice
Currency Markets¶
- Higher rates → currency appreciates (attracts capital)
- Lower rates → currency depreciates (capital flows out)
- This is the basis of the carry trade
Key Takeaways¶
- Central banks use interest rates as their primary tool to manage the economy
- QE extends monetary policy beyond the zero lower bound
- There’s always a lag between policy changes and their effects (6-18 months)
- Understanding monetary policy is essential for anyone working in finance
- Markets often react more to expectations of policy changes than the changes themselves