Worked-example setupScope and assumptions
- Each scenario uses one unchanged fictional broad index series and equal comparison intervals.
- The prior rate is supplied rather than inferred from a single endpoint pair.
- Period
- Three fictional annual comparisons
- Units
- index points and unit-free rates
- Rounding
- Full precision internally; rates to two decimal percentage points
Scenario one rises from 120 to 123, a 2.5% positive rate. Because the comparable prior rate was 4%, prices are still rising but inflation is slowing: disinflation.
Scenario two falls from 125 to 122.5, a -2% rate: deflation. Scenario three rises 6% after a 3% prior rate: accelerating inflation. An index above 100 has no classification by itself; 100 is a reference scale, not a “normal” price.
These signs do not identify causes or welfare. The analyst still needs index scope, weights, adjustment, release vintage, exposures, debts, wages, quantities, expectations, and evidence before translating the pattern into consequences.
Verified calculation · economics foundations analysis
The curriculum loader recomputed this example before it entered the site build. Expand any structured input to inspect the stated facts.
- price index changes
- 3 fields
Inspect data
{
"accelerating_positive_rate": {
"end_index": 106,
"prior_period_inflation_rate": 0.03,
"start_index": 100
},
"negative_rate": {
"end_index": 122.5,
"prior_period_inflation_rate": 0.02,
"start_index": 125
},
"slowing_positive_rate": {
"end_index": 123,
"prior_period_inflation_rate": 0.04,
"start_index": 120
}
}Recomputed result
| Measure | Value |
|---|---|
| accelerating positive rate disinflation | 0 |
| accelerating positive rate inflation rate | 0.06 |
| negative rate deflation | 1 |
| negative rate inflation rate | -0.02 |
| slowing positive rate disinflation | 1 |
| slowing positive rate inflation rate | 0.025 |
| slowing positive rate positive inflation | 1 |