Parity Principle

The parity principle is a cornerstone of substantive fairness in dismissal law. Item 7(b)(iii) of Schedule 8 to the Labour Relations Act 66 of 1995 directs a commissioner to consider whether the rule or standard has been consistently applied by the employer. Inconsistency is one of the fastest routes to a finding of substantive unfairness.

Two branches have emerged in case law. Historical inconsistency — raised in NUM v Amcoal Colliery (2000) 21 ILJ 1057 (LAC) — asks whether the employer has condoned similar misconduct by other employees in the past. Contemporaneous inconsistency — the focus of SACCAWU v Irvin & Johnson (1999) 20 ILJ 2302 (LAC) — asks whether co-perpetrators of the same incident received different sanctions. In both, the employer must justify the difference on objective grounds: different service records, different degrees of involvement, different mitigating factors, or different roles.

For contract drafting, the parity principle supports clauses that preserve managerial discretion ("each case shall be considered on its own merits, having regard to the employee\'s service record, the gravity of the offence, and any mitigating or aggravating circumstances"). In a disciplinary hearing the employer should place comparators on the record and explicitly explain any differentiation. Failure to do so typically results in reinstatement under section 193 of the LRA.