How an Economy Is Measured · Lesson 6 of 6
Reading the impact tier: a backward-looking measure, not a verdict
One concept: the impact tier as a computed statistic
Why it matters
Beside every indicator on Kitalpha’s calendar sits a small label: high, medium or low. The newest CPI row carries "high" with a score of 2.05 basis points, and the methodology record publishes the calculation behind it, version 2026-07-release-day-excess-trailing5y-v2. A first-time reader tends to hear the label as a verdict: high impact means bad news, or means this release matters to me. The label says neither. What it does say, and how it is computed from past Treasury moves, is the one idea of this lesson.
The concept
An impact tier is the output of one fixed calculation on stored records. Nothing else enters it: no editor scores the release, no survey ranks it, and no reader’s circumstances are consulted. The calculation has four parts, and the methodology record publishes every number it uses.
The first part is the measure. On each of the indicator’s past release days, take the closing 10-year U.S. Treasury yield from the Treasury’s par yield curve and subtract the previous trading day’s close. Keep the size of the change and drop its sign, so that a move up and a move down of the same size count the same; this is the absolute move, in basis points, where a basis point is one hundredth of a percentage point. The second part is the baseline. Yields move a little on every day, release or not, so the average absolute move on release days is compared with the same average taken over quiet days, trading days on which none of the tracked indicators released. The release-day average minus the quiet-day average is the excess. An excess near zero says the indicator’s release days looked like any other day; a large excess says they did not.
Two details keep the sample honest. A day on which two tracked indicators released is excluded from both, because a closing price cannot say which release the move belonged to; the days that remain are the clean sample, and its size is published as a count. And the same excess is computed a second time on the 2s10s spread, the 10-year yield minus the 2-year yield, because a policy decision moves short yields far more than long ones; the published score is the larger of the two excesses, and a field records which one it was.
The third part is the window. The score is cut over the trailing five years, the regime a reader actually stands in, because the market’s habit of reacting to a release changes over decades. Where five years hold fewer clean days than the published minimum, the method falls back to the full history and the row says so. Below the minimum in either window, no tier is published at all; the row simply shows none, which is a different statement from low. The fourth part is the tier itself: the score bucketed against two fixed cutoffs in basis points, published and frozen.
Read this way, a tier answers one narrow question: over the stated window, how much more did the Treasury curve move on this indicator’s release days than on an ordinary day? It has no sign, so it cannot mean good or bad. It is about the bond market, not about any reader. And it is backward-looking, so it says nothing about the next print. The bars below place two indicators’ release-day averages against the baseline; look for how far each bar extends beyond the baseline bar, since that excess, not the bar’s whole length, is what the tier is cut from.
| Item | Value |
|---|---|
| Quiet-day baseline | 4.53 |
| CPI release days | 6.58 |
| PPI release days | 4.76 |
Worked example
Take the methodology record for the window ending 2026-09-15 and the newest CPI row, released 2026-09-11. The steps below read the quiet-day baseline, CPI’s release-day average, the excess between them, the size of CPI’s clean sample, and how many indicators in the window carry a tier at all. Every figure comes from the named record.
Record: Release impact methodology · as of · Kitalpha, computed from U.S. Treasury par yields
- Quiet-day baseline: the mean absolute move in the 10-year yield on days with no tracked release, in basis points, from the methodology record 4.53
- CPI: the mean absolute 10-year move on its clean release days, in basis points, from the CPI row 6.58
- CPI: release-day mean minus the quiet-day baseline, in basis points 2.05 The excess is the number the tier is cut from; it is a size, never a direction.
- CPI: clean release days in the sample 55 Days on which another tracked indicator also released are excluded from both, so the sample is smaller than the number of releases.
- Indicators with a published tier in the trailing window, from the methodology record 9
- Indicators with no tier, because their clean sample is below the minimum 2
Read the third line as the whole of the tier’s raw material: an average size of daily move with an ordinary day’s movement taken out, in basis points. The fourth line is why the sample matters; excluding shared release days shrinks it, and an indicator whose clean count falls below the minimum gets no tier rather than a shaky one, which is what the last two lines count across the window. Nothing here carries a sign, and nothing here looks forward.
Faded example
Now a second row: the newest producer price index release, published 2026-09-10, which carries the tier "low". The baseline and PPI’s release-day average are given. Complete the last step: PPI’s excess over a quiet day.
Second record: Producer Price Index, August 2026 · as of
- Quiet-day baseline, in basis points, from the methodology record4.53
- PPI: the mean absolute 10-year move on its clean release days, in basis points, from the PPI row4.76
- bp Tolerance ±0.05 bp
Reveal the answer and the explanation
0.23 — Subtract the baseline from PPI's release-day mean. Both figures are already in basis points and both are sizes of moves with the sign dropped, so the difference is an excess move, and its sign says only whether PPI's release days moved the yield more or less than a quiet day did over the window.
Stored on this device only; not graded.
Retrieval check
Mark your confidence before each answer. Every option carries an explanation; read the ones you rejected too.
-
1. The CPI row on the calendar carries a high tier. Read against the methodology record, that tier states:
Choose your confidence first. -
2. Using the CPI row and the methodology record, subtract the quiet-day baseline from CPI's mean absolute 10-year move on its clean release days. Enter the excess in basis points to two decimals.
Source record: Consumer Price Index, August 2026 (as of 2026-09-11)
Tolerance ±0.05 bpChoose your confidence first. -
3. An indicator on the calendar shows no tier at all. According to the methodology record, that means:
Choose your confidence first. -
4. The methodology record names a primary window and a fallback window. The tier on a row is computed:
Choose your confidence first.