With the Taylor rule (α = 0.5, β = 0.5) and r* = 2%, inflation rises 2 percentage points above its target while output is at potential. By how much should the nominal interest rate change?
ABy 1 percentage point — the policy response is α × Δπ = 0.5 × 2
BBy 2 percentage points — nominal rates match inflation one-for-one to hold real rates constant
CBy 3 percentage points — the rate rises by the inflation increase (2pp) plus the policy response (0.5 × 2pp = 1pp)
DBy 4 percentage points — the maximum response needed to reverse the inflationary shock quickly
The Taylor rule formula is i = r* + π + α(π − π*) + β(y − y*). When inflation rises 2pp above target and output is at potential, the nominal rate rises by: 2pp (direct inflation pass-through in the π term) + α × 2pp (policy response) = 2 + 0.5×2 = 3pp. Since inflation rose 2pp but the nominal rate rose 3pp, the real interest rate rises by 1pp. This is the Taylor principle in action: monetary policy actually tightens only when real rates rise, which requires nominal rates to increase by MORE than the inflation increase.
Question 2 Multiple Choice
The Taylor rule prescription falls to −3% during a severe recession. The central bank cannot set negative rates and holds at 0%. What does this situation illustrate?
AThe Taylor rule was incorrectly calibrated and should not be applied during recessions
BThe zero lower bound constraint, which exhausts conventional rate-cutting capacity and motivates unconventional tools like quantitative easing
CThe output gap component of the Taylor rule is overweighted and distorts the prescription downward
DRicardian equivalence, which offsets the expansionary effects of low interest rates
When the prescribed rate is negative, the central bank would need to lower rates further to provide appropriate stimulus — but conventional monetary policy cannot set negative rates (the zero lower bound). This is precisely the constraint that motivated unconventional tools: quantitative easing (buying longer-term assets to lower long-term rates), forward guidance (committing to keep rates low), and in some countries, explicit negative interest rate policy. The Taylor rule's prescription falling below zero reveals the limits of conventional policy, not a flaw in the rule itself.
Question 3 True / False
If a central bank raises its nominal interest rate by exactly the same number of percentage points as the rise in inflation, the real interest rate remains unchanged and monetary policy has not effectively tightened.
TTrue
FFalse
Answer: True
The real interest rate equals the nominal rate minus inflation (Fisher equation). If both rise by the same amount, real rates are unchanged — lending remains equally attractive, borrowing equally cheap, and there is no actual tightening. This is precisely the failure mode the Taylor principle is designed to prevent. A passive policy that merely matches nominal rates to inflation leaves real rates constant, failing to cool demand or reduce inflation. The Taylor rule's α > 0 coefficient ensures nominal rates rise by MORE than inflation, so real rates actually increase.
Question 4 True / False
Central banks that follow the Taylor rule literally compute the formula at each policy meeting and set rates mechanically to the prescribed value.
TTrue
FFalse
Answer: False
The Taylor rule is a benchmark and analytical framework, not a mechanical algorithm. Central banks use the rule to evaluate whether policy is roughly appropriate and to communicate the logic behind rate decisions, but they do not follow it mechanically. In practice, they use forecasts rather than current data (forward-looking Taylor rules), adjust rates gradually rather than jumping to the prescription (inertial rules), and incorporate financial conditions, exchange rates, and other variables not in the basic formula. Taylor himself designed it as a description of systematic policy behavior, not a prescription to be executed blindly.
Question 5 Short Answer
What is the 'Taylor principle,' and why does violating it cause monetary policy to destabilize rather than stabilize inflation?
Think about your answer, then reveal below.
Model answer: The Taylor principle states that the central bank must raise the nominal interest rate by more than one-for-one with any rise in inflation, so that the real interest rate (nominal minus inflation) actually increases. If the central bank raises nominal rates by less than the increase in inflation, real rates fall. Lower real rates reduce the cost of borrowing, stimulate demand, and generate more inflation — the opposite of the intended effect. A passive policy that merely tracks inflation leaves real rates unchanged and provides no corrective force. The Taylor principle ensures that inflation-fighting is genuine: only when real rates rise does policy actually cool spending and bring inflation back to target.
The principle has a deep connection to equilibrium stability. Macroeconomic models show that an economy with a central bank that violates the Taylor principle has 'indeterminate' equilibria — small shocks can lead to self-fulfilling inflationary spirals. A central bank that commits credibly to raising real rates when inflation rises anchors expectations and gives the economy a stable equilibrium. The 'Great Inflation' of the 1970s is often attributed in part to the Fed's failure to raise real rates sufficiently when inflation rose.