What CIBI measures
CIBI looks across eight mutually exclusive top-level CPI-U major groups rather than averaging them into one inflation rate. For each group, it asks whether year-over-year inflation is higher than it was one year earlier.
The score is the percentage of those eight groups where that is true. Because the denominator is fixed at eight, the index moves in 12.5-point increments. A reading of 62.5 means five of eight major groups have faster year-over-year inflation than they did a year earlier.
Why use acceleration breadth
Headline and core CPI tell you the aggregate rate of price change. CIBI asks a different question: whether faster inflation is becoming widespread across major consumer categories or remains concentrated in a smaller part of the basket.
The reviewed acceleration-breadth formulation was chosen because it stayed meaningfully less tied to simple CPI level measures than the rejected above-2% breadth version, while avoiding the persistent upper-end saturation seen in positive-inflation breadth.
Source timing and historical boundaries
CIBI uses direct U.S. Bureau of Labor Statistics CPI-U indexes for the U.S. city average, not seasonally adjusted. A monthly reading becomes historically available only on the official CPI release date retained from the BLS release archive.
The reviewed history uses the post-1998 CPI item structure. January through August 2000 are excluded from point-in-time evidence because current BLS bulk history reflects a later correction, and October 2025 remains an explicit unpublished reference month rather than a synthetic observation.
What CIBI does not tell you
CIBI gives each major CPI group one breadth vote regardless of its expenditure weight, so it measures participation across categories rather than each category's contribution to headline CPI.
It is a descriptive inflation-participation benchmark, not a forecast of future inflation, recession probability, market returns, or a standalone trading signal.
Low example
0.0
Dec 12, 2023
Median score
50.0
Selected sample
Average score
46.7
Selected sample
High example
100.0
Apr 12, 2022
Regime frequency in this sample| Regime | Observations | Share |
|---|
| Widespread Cooling | 12 | 21.4% |
| Mostly Cooling | 14 | 25.0% |
| Mixed Inflation | 7 | 12.5% |
| Broad Acceleration | 17 | 30.4% |
| Pervasive Acceleration | 6 | 10.7% |
These frequencies describe the selected historical sample. They are not probabilities for future returns or market turning points.
