---
title: "Compute Disparate Impact Metrics"
method: POST
path: "/v1/tools/compute_disparity_metrics"
tags: ["TODO_TAGS_REVIEW", "TODO_AP2_EXPORT_REVIEW"]
---

# Compute Disparate Impact Metrics

`POST /v1/tools/compute_disparity_metrics`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/compute_disparity_metrics`
- Auth: none declared

Computes three fair lending disparate impact metrics from aggregate lending counts: 4/5ths (80%) rule (adverse_impact_ratio) per EEOC 29 CFR §1607.4(D), z-statistic for statistical significance of the approval-rate difference, and standardised mean difference (Cohen's d). Inputs are aggregate counts only; no individual applicant records, names, demographic identifiers, or scores. ZERO PII BY CONSTRUCTION. EEOC Uniform Guidelines on Employee Selection Procedures (29 CFR §1607), HMDA/Reg C.

**Tool URL:** https://ainumbers.co/chaingraph/art-229-compute-disparity-metrics.html

## Request body

- object
  - `group_a_approvals` number
  - `group_a_label` unknown, required
  - `group_a_total` number
  - `group_b_approvals` number
  - `group_b_label` unknown, required
  - `group_b_total` number

## Response `200`

Successful tool execution result

- object
  - `adverse_impact_ratio` number
  - `four_fifths_flag` boolean
  - `four_fifths_result` string
  - `four_fifths_threshold` number
  - `group_a` object
    - `approval_rate` number
    - `approvals` integer
    - `label` string
    - `total` integer
  - `group_b` object
    - `approval_rate` number
    - `approvals` integer
    - `label` string
    - `total` integer
  - `n_total` integer
  - `odds_ratio` number
  - `pii_note` string
  - `pooled_proportion` number
  - `regulatory_basis` string
  - `standardized_mean_difference` number
  - `table_source` string
  - `table_version` string
  - `two_proportion_z` number
  - `z_critical_flag_onetail_05` boolean
  - `z_critical_flag_twotail_05` boolean
  - `zero_pii_confirmation` string

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)