# Unit Return Rate – Local Finite-Change Elasticity Calculator

> Unit Return Rate – Local Finite-Change Elasticity Calculator is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Computes the local finite-change elasticity of the unit return rate with respect to a small percentage change in either returned_units or sold_units, using supplied retail figures.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-sector-retail-unit-return-elasticity?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/unit-return-rate-local-finite-change-elasticity-calculator-05fd6ee6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TuBnZ61d7mlsXL_roMPpp

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability unit-return-rate-local-finite-change-elasticity-calculator-05fd6ee6 -d '<json body>'
```

Example prompt: Calculate the local finite-change elasticity of the unit return rate for my retail store — baseline is 100 sold units and 5 returned units, and I want to see the elasticity with a 1% step change in returned_units.

## When to prefer this

Choose this endpoint when you need a lightweight, local elasticity computation on unit return rate using only supplied retail figures — no live platform integration or account access needed. It is ideal for scenario analysis, sensitivity checks, and quick quantitative assessments of how return rates respond to marginal changes in returns or sales volume, at extremely low cost ($0.01 USDC per call).

## Known failure modes

- sold_units of zero or below minimum causes validation error since it is in the denominator
- step_percent outside the 0.01–10 range returns a validation/schema error
- Missing required baseline fields (returned_units or sold_units) causes a 400-level error
- Invalid field enum value (not 'returned_units' or 'sold_units') returns a schema validation error
- returned_units exceeding 1,000,000,000,000 or negative values fail schema validation

## How this service works

Unit return rate - Local finite-change elasticity: Local finite-change elasticity for Unit return rate. Supplied retail figures only. Local calculation and scenario analysis; no live inventory, account access, platform fee lookup or order execution. One of 25 profiles or calculations across 20 shared operations in this sector. 0.01 USDC includes one bounded local finite-change elasticity deliverable.

## Output

Returns a local finite-change elasticity value representing how the unit return rate (returned_units / sold_units) responds to a small percentage perturbation in the selected field (returned_units or sold_units). The result quantifies the sensitivity of the return rate to marginal changes at the specified baseline, enabling scenario analysis without live inventory or order data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "field": {
   "enum": [
    "returned_units",
    "sold_units"
   ],
   "type": "string",
   "default": "returned_units"
  },
  "baseline": {
   "type": "object",
   "default": {
    "sold_units": 100,
    "returned_units": 5
   },
   "required": [
    "returned_units",
    "sold_units"
   ],
   "properties": {
    "sold_units": {
     "type": "number",
     "default": 100,
     "maximum": 1000000000000,
     "minimum": 0,
     "exclusiveMinimum": 0
    },
    "returned_units": {
     "type": "number",
     "default": 5,
     "maximum": 1000000000000,
     "minimum": 0
    }
   },
   "additionalProperties": false
  },
  "step_percent": {
   "type": "number",
   "default": 1,
   "maximum": 10,
   "minimum": 0.01
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/unit-return-rate-local-finite-change-elasticity-calculator-05fd6ee6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)