---
id: "prereq-productivity-formula"
type: "prereq"
source_timestamps: ["§ 2. Ensure that performance evaluation and management systems are focused on output rather than input"]
tags: ["economics", "business-metrics"]
related: ["claim-input-metrics-punish-efficiency", "concept-clandestine-ai-use"]
reason: "Forms the mathematical basis for the argument that performance management systems must shift from input to output."
sources: ["adoption"]
sourceVaultSlug: "hbr-seg-adoption"
originDay: 9
articleStem: "hbr-edu-36-team-collaborate-with-ai"
sourceUrl: "https://hbr.org/2024/11/set-your-team-up-to-collaborate-with-ai-successfully"
sourceTitle: "Set Your Team Up to Collaborate with AI Successfully"
---
# Productivity Formula (Output / Input)

**Prerequisite concept.** The author explicitly defines productivity as **output divided by input** (productivity = output / input).

**Why it's needed:** A basic grasp of this relationship is required to understand why measuring only *input* (hours worked) breaks down when technology drastically reduces the input required to achieve the same output. If input falls (AI does the job in 40% less time) but the numerator (output) is held constant, measured productivity *rises* — yet input-based evaluation misreads the freed time as slacking. This is the mathematical backbone of the claim that [[claim-input-metrics-punish-efficiency]] and the driver of [[concept-clandestine-ai-use]]. *(Enrichment: technology's historical purpose is precisely to reduce input for a given output.)*