I had assumed stack ranking was specifically designed to force managers to fire low performers, without relying on their individual judgment. Since nobody likes to fire, this overcomes the inertia, and since relying on personal judgment exposed you to legal risk and principle agent problems, a simple rule was substituted. The author’s proposal to go back to managerial discretion would of course be incompatible with that intention.

I do wonder whether those implementing stack ranking are really that committed to a particular statistical model of employee productivity, or if they’re trying to solve a human and legal problem with an algorithm.