Hong Life CalculatorsUnderstanding the Taylor rule calculator — concept and principle
The Taylor rule is a simple formula that suggests where a central bank's policy interest rate should be, given inflation and the output gap. Economists and market watchers use it as a benchmark to judge whether monetary policy looks tight or loose.
How it is calculated
R = rLR + π + 0.5 × (π − π*) + 0.5 × (y − yP)
- rLR: neutral real policy rate in the longer run.
- π: inflation over the past four quarters; π*: inflation target (usually 2%).
- y − yP: output gap in percent.
- The balanced-approach rule uses a weight of 1 on the output gap.
- Real policy rate = suggested rate − inflation.
The principle
John Taylor showed in 1993 that a simple rule described US policy rates well. The rate starts from a neutral level (neutral real rate plus inflation) and moves up when inflation is above target or the economy runs above potential. Because the inflation term has a total weight of 1.5, a 1-point rise in inflation raises the nominal rate by 1.5 points, so the real rate rises and cools demand. This is known as the Taylor principle.
Worked example
Default inputs: neutral real rate 1%, inflation 3%, target 2%, output gap −0.5%, Taylor (1993) rule, current policy rate 3.75%.
- Inflation term = 0.5 × (3 − 2) = 0.5.
- Output-gap term = 0.5 × (−0.5) = −0.25.
- Suggested rate = 1 + 3 + 0.5 − 0.25 = 4.25%.
- Real policy rate = 4.25 − 3 = 1.25%.
- Gap to the current rate = 4.25 − 3.75 = 0.5 points: the rule points higher than now.
| Inflation over the last 4 quarters (%) | Policy rate the rule suggests |
|---|---|
| 0.75 | 0.88% |
| 1.5 | 2% |
| 2.25 | 3.13% |
| 3 | 4.25% |
| 3.75 | 5.38% |
| 4.5 | 6.5% |
| 6 | 8.75% |
How to read the result
A suggested rate above the actual rate means policy is looser than the rule implies, and vice versa. Central banks do not follow rules mechanically: they consider forecasts, financial conditions and risks. The result depends heavily on the neutral rate and output gap, which are uncertain estimates; try different values to see the range.
Common mistakes
- Treating the rule as what the central bank will do.
- Using a neutral rate or output gap estimate without noting its uncertainty.
- Mixing headline and core inflation without saying which.
- Ignoring that negative suggested rates cannot be fully applied near zero.
Frequently asked questions
What is the Taylor rule formula?
R = neutral real rate + inflation + 0.5 × (inflation − target) + 0.5 × output gap.
Does the Federal Reserve follow the Taylor rule?
The Fed publishes several policy rules as reference points in its Monetary Policy Report but does not follow any rule mechanically.
What is the Taylor principle?
The nominal rate should rise more than one-for-one with inflation so that the real rate increases.
Sources: Taylor, J. B. (1993). Discretion versus Policy Rules in Practice. Carnegie-Rochester Conference Series on Public Policy, 39. · Board of Governors of the Federal Reserve System, Policy Rules and How Policymakers Use Them