Description
Measure a supplied preferential-tariff margin in fraction and percentage points.
International economic quantities depend on currency quotation, valuation base, denominator, accounting boundary and reporting period. A unit value differs from a comparable price, while import penetration can exceed one under a supplied absorption definition. Tax, ownership and counterfactual terms remain explicit scenarios rather than verified economic facts.
Measure a supplied preferential-tariff margin in fraction and percentage points.
When to use this tool
Use Preferential Tariff Erosion Margin when you already have referenceTariffFraction, preferentialTariffFraction and need to measure a supplied preferential-tariff margin in fraction and percentage points.
How to use the tool and how it works
- Enter referenceTariffFraction, preferentialTariffFraction. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read preferenceMarginFraction, percentagePointMargin. Use the output convention below.
Require nonnegative reference/preferential fractions; return reference-preferential and 100 times that difference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| referenceTariffFraction | Reference Tariff Fraction | Required. Finite number; minimum 0. |
| preferentialTariffFraction | Preferential Tariff Fraction | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| preferenceMarginFraction | referenceTariffFraction-preferentialTariffFraction, a signed decimal fraction. | Required. Finite number. |
| percentagePointMargin | 100*preferenceMarginFraction, expressed in percentage points. | Required. Finite number. |
{
"input": {
"referenceTariffFraction": 0.1,
"preferentialTariffFraction": 0.05
},
"output": {
"preferenceMarginFraction": 0.05,
"percentagePointMargin": 5
}
}Limitations and assumptions
- A negative margin is retained; the inputs are decimal rates rather than percentage numbers, and no actual preference entitlement or rate is selected.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use the complete underlying accounts, price indices, trade definitions and applicable source rules for an actual comparison. Reconcile valuation, timing, currency and coverage before interpreting a residual or weighted contribution as a broader economic result.
References
Similar or alternative tools
- Tariff Cif Fob Price Base
Apply a supplied tariff to a goods-only or freight-and-insurance-inclusive base.
- International Price Numeraire Rescale
Rescale a price into a supplied numeraire.