Source: https://guthlabs.ai/docs/instruments/real-gdp-gdp-deflator-converter/

instrument / verified-clean

# Real GDP / GDP Deflator Converter

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/real-gdp-gdp-deflator-converter/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/real-gdp-gdp-deflator-converter/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/real-gdp-gdp-deflator-converter/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/real-gdp-gdp-deflator-converter/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Finance, Economics & Business (educational only — never individualized investment, tax, or legal advice)

**Tranche**: tranche-5

**Evidence ID**: t5-178

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The core real-GDP conversion formula is standard under the stated index convention. The specification needs the inverse deflator formula, an explicit implied-inflation definition, period/frequency handling, and validation rules before the full claimed instrument can be verified. The educational-only label is appropriate.

### Formula and scope findings

- real_GDP=nominal_GDP/(deflator/100) is correct only when deflator is an index level with 100 as the base-period value.

- The claimed ability to solve the deflator lacks an explicit inverse formula: deflator=(nominal_GDP/real_GDP)*100.

- The claimed implied-inflation output has no specified formula. The standard interpretation is inflation=((current_deflator/previous_deflator)-1)*100, but the required periods and frequency are unspecified.

### Unit assumptions

- Nominal GDP and real GDP must use the same currency and scale, such as both USD or both billions of USD.

- The deflator is a dimensionless index level, not a percentage rate; 100 represents the base period.

- The real-GDP output retains the nominal-GDP currency and scale.

- Implied inflation is assumed to be the percentage change in the GDP deflator between two specified periods; it cannot be labeled annual unless the periods are one year apart.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

A zero deflator creates an undefined division and must be rejected. The specification also has no genuine formula branch, and ambiguous ratio-versus-index input can produce materially different results if conventions are not explicit.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "nominal_GDP": 2400000000000,
    "deflator_index": 120,
    "currency": "USD"
  },
  "expected_outputs": {
    "real_GDP": 2000000000000,
    "currency": "USD"
  },
  "working": "deflator/100 = 120/100 = 1.2\nreal_GDP = 2,400,000,000,000 / 1.2\nreal_GDP = 2,000,000,000,000 USD"
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`