AI Hiring Glossary
Four-Fifths Rule
Four-Fifths Rule (80% Rule)
A guideline for determining adverse impact in employment selection. If the selection rate for a protected group is less than 80% (or 4/5ths) of the selection rate for the group with the highest rate, adverse impact may be indicated.
Why This Matters for Employers
This is the standard metric used in bias audits under NYC Local Law 144 and is commonly applied to evaluate AI hiring tools for potential discrimination.
Related Laws & Regulations
EEOC Uniform Guidelines
Federal
NYC Local Law 144
New York City
Examples in Practice
If 60% of white candidates pass screening but only 45% of Black candidates pass, the impact ratio is 75% (45/60) — below the 80% threshold
Comparing selection rates across gender, race, and ethnicity categories
How EmployArmor Helps
Understanding Four-Fifths Rule is just the first step. EmployArmor helps you implement compliance for all AI hiring regulations.
Compliance Assessment
Find out which laws apply to your AI hiring tools and what you need to do to comply.
Documentation Templates
Get ready-to-use templates for impact assessments, notifications, and audit preparation.