ECON30005 · Money and Banking
Central Banking and the Tools of Monetary Policy
Week 7 covers the structure of central banking and the monetary-policy toolkit: open-market operations, the discount rate, interest on reserves, and unconventional tools (QE, forward guidance), organised as a chain from tools to instruments to intermediate targets to goals. It sets out how the policy rate is determined and the Taylor rule, including the Taylor principle that nominal rates must rise more than one-for-one with inflation. Expect true/false on the tools and IOR, short essays on how policy sets the money supply, and a Taylor-rule computation.
What this chapter covers
- 01Core central-bank functions: conduct monetary policy, issue currency, lender of last resort, payments, banker to government
- 02Central-bank independence: goal independence versus instrument/operational independence, and its link to lower, more stable inflation
- 03The policy rate as an overnight interbank/reserve rate (US federal funds rate; Australia's cash rate)
- 04Open-market operations: repos, reverse repos and outright purchases/sales to steer the policy rate
- 05The discount rate as a ceiling and interest on reserves (IOR) as a floor — the corridor for the policy rate
- 06Reserve requirements (zero in the US since 2020 and in Australia) and why they are no longer the main lever
- 07Unconventional tools at the zero lower bound: quantitative easing and forward guidance
- 08The Taylor rule i = π + r* + w_π(π − π*) + w_y(y − y*) and the Taylor principle (w_π > 0)
A Taylor-rule prescription for the policy rate
- +1Write the rule: i = π + r* + w_π(π − π*) + w_y(y − y*). The prescribed nominal rate is inflation plus the neutral real rate plus weighted responses to the inflation gap and the output gap.
- +1Inflation-gap term: w_π(π − π*) = 0.5·(5 − 2.5) = 0.5·2.5 = 1.25 percentage points. Inflation is above target, so this term is positive.
- +1Output-gap term: w_y(y − y*) = 0.5·(−1) = −0.5 percentage points. Output is below potential, pulling the rate down. Combine everything: i = 5 + 1 + 1.25 − 0.5 = 6.75%.
- +1Verdict: the rule prescribes 6.75%, above the π + r* = 6% baseline, so it calls for tightening. This illustrates the Taylor principle — because w_π > 0, when inflation rises above target the nominal rate rises more than one-for-one, so the real rate rises and inflation is stabilised.
Key terms
- Policy rate
- The short-term interest rate a central bank targets — the US federal funds rate or Australia's cash rate — an overnight interbank/reserve rate. Open-market operations and standing facilities keep the market rate at this target.
- Open-market operations (OMO)
- Purchases and sales of securities (mostly government bonds) that adjust the supply of reserves to hold the policy rate at target. Repos inject reserves and push the rate down; reverse repos drain reserves and push it up.
- Interest on reserves (IOR)
- The rate a central bank pays on banks' reserve balances. It acts as a floor for the policy rate (banks will not lend below it) and, with the discount rate as a ceiling, defines a corridor for the rate even when reserves are abundant.
- Quantitative easing (QE)
- Large-scale outright purchases of longer-term securities used near the zero lower bound to lower long-term rates and ease financial conditions. Distinct from OMO, which fine-tunes reserves to hold the policy rate.
- Taylor rule
- A monetary-policy reaction function i = π + r* + w_π(π − π*) + w_y(y − y*) that sets the policy rate as the neutral rate plus weighted responses to the inflation and output gaps.
- Taylor principle
- The requirement that a central bank raise nominal rates more than one-for-one with inflation (w_π > 0, so d i/dπ > 1), which makes the real rate rise when inflation rises and is critical to stabilising inflation.
Central Banking and the Tools of Monetary Policy FAQ
How does a central bank actually set the policy rate?
By managing the market for reserves. In a corridor or floor system the central bank uses open-market operations (mostly repos and reverse repos) to adjust reserve supply, and it sets standing-facility rates — interest on reserves as a floor and the discount rate as a ceiling — so that the overnight interbank rate settles at target. It does not decree the rate directly; it makes the target rate the market-clearing rate for reserves.
Why is the reserve requirement no longer the main tool?
Because several major economies, including the US (since March 2020) and Australia, have set the required-reserve ratio to zero, and because the modern view is that lending is not reserve-constrained. Central banks now steer the policy rate through open-market operations and, especially, interest on reserves, which sets a floor even when reserves are abundant. The reserve requirement survives in the textbook money-multiplier appendix but is not how contemporary policy operates.
What is the Taylor principle and why does it matter?
The Taylor principle says the central bank must raise the nominal policy rate by more than one percentage point for each percentage point of extra inflation (the inflation-response weight w_π must be positive). If it does, a rise in inflation raises the real interest rate, which cools demand and pulls inflation back — stabilising. If it does not, higher inflation lowers the real rate, stimulating demand and letting inflation spiral. Meeting the principle is widely seen as central to successful post-1980s monetary policy.
Can AI help me with central-banking tools in ECON30005?
Yes. Sia can compute Taylor-rule prescriptions on fresh numbers, explain the corridor system and how interest on reserves sets a floor, and contrast open-market operations with quantitative easing. Use it to rehearse the calculations and the institutional detail; it does not complete graded quizzes for you, and you should confirm assessment rules on Canvas.
Exam move
Separate the institutions from the mechanics. On the institutional side, keep a compact card of central-bank functions and the goal-versus-instrument independence distinction, plus the tools (OMO, discount rate, IOR, QE, forward guidance) and where each sits — repos inject reserves, IOR is the floor, the discount rate the ceiling. On the mechanics side, over-practise the Taylor rule: plug in gaps and weights, watch the signs, and always test the Taylor principle by checking d i/dπ = 1 + w_π > 1. Be ready for the true/false that reserve requirements are the main modern lever (false — they are often zero) and that IOR sets a floor (true). This week feeds directly into transmission and inflation targeting, so tie the policy rate to how it reaches output and inflation. Confirm the exam structure on Canvas.
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