Goodhart's Law is when a measure becomes a target, it ceases to be a good measure. It sits in the Incentives dimension (INC) of the Human Behavior Taxonomy™ as element HBT-INC-0137, within the Universal Pattern Perverse Pattern family. The core principle: when a measure becomes a target, it ceases to be a good measure. In incentive terms, it matters because it changes the payoff people perceive before they choose — which means it can be designed for, or exploited.
Scientific Definition
When a measure becomes a target, it ceases to be a good measure.
Plain-English Definition
When a measure becomes a target, it ceases to be a good measure.
Feynman Explanation
The metric you optimize is the metric that betrays you.
Core Principle
When a measure becomes a target, it ceases to be a good measure.
Mechanisms
Pending editorial review.
When a measure becomes a target, it ceases to be a good measure.
Pending editorial review.
Pending editorial review.
Every KPI eventually corrodes if attached to comp without offsetting metrics.
Pending editorial review.
Pending editorial review.
Inputs (Triggers)
Pending editorial review.
Outputs (Behaviors)
Pending editorial review.
Behavioral Signature
The metric you optimize is the metric that betrays you.
Examples
- Customer service teams optimizing 'time to close ticket' produce un-resolved tickets, fast.
- Every KPI eventually corrodes if attached to comp without offsetting metrics.
Pending editorial review.
Original analysis from The Incentives Lab — how this element behaves inside real payoff structures.
Why this element matters to incentive design
When this element shows up in a diagnostic, the instinct is to train people out of it. Training rarely moves it. The mechanism underneath it is straightforward: when a measure becomes a target, it ceases to be a good measure. You can recognize it in the field by its signature: the metric you optimize is the metric that betrays you. Every element in the Incentives dimension changes the perceived payoff of an action before the action happens, which is exactly where incentive design has leverage.
How it gets exploited
Left undesigned, every KPI eventually corrodes if attached to comp without offsetting metrics. It is amplified whenever every KPI eventually corrodes if attached to comp without offsetting metrics. Inside organizations that shows up as every KPI eventually corrodes if attached to comp without offsetting metrics. The pattern is the same one Goodhart's Law describes: the measurable proxy attracts the effort, and the purpose behind it quietly loses funding.
How the Lab designs around it
The redesign move is to pair every metric with a counter-metric. Rotate KPIs. Audit gamification. Watch for it at the boundaries: handoffs, promotions, incident reviews, and budget cycles are where this element gets its power.
Famous Experiments
Pending editorial review.
Design Principles
- Pair every metric with a counter-metric. Rotate KPIs. Audit gamification.
Measurement Approaches
Pending editorial review.
Evidence
Pending editorial review.
Pending editorial review.
The Perverse Incentive Lens™
How this behavior is exploited — and how to redesign around it.
- Pair every metric with a counter-metric. Rotate KPIs. Audit gamification.
Pending editorial review.
Pending editorial review.
Interactive Mini Network
Click any neighbor to re-center the graph and follow the threads of connection.
Knowledge Graph Neighbors
Auto-linked to the rest of the Human Behavior Taxonomy by family, domain, dimension, and shared keywords.
Once-a-year feedback rewards once-a-year behavior.
The more a quantitative indicator drives decisions, the more it distorts the process it measures.
Donors penalize 'overhead'; charities under-invest in capacity.
Donors penalize 'overhead' and starve capacity that produces outcomes.
A reward designed to reduce X produces more X.
Squeezing all slack from a system optimizes throughput but eliminates resilience.
'Equal value' exchanges incentivize subjective appraisal gaming to trade low-utility land for high-value public assets.
Deep specialization improves local output but breaks cross-domain understanding.
Greedy improvement loops climb hills that aren't the highest hill.
When rewards don't match stated values, culture quietly decays toward what is rewarded.
Insulation from risk changes the risks people take.
Systems with weak corrective feedback drift unchecked into failure modes.
Where Goodhart's Law is cited in the corpus
Essays, field guides, and diagnostics from The Incentives Lab that apply this element.
- Field guideIncentives: definition, types, examples
The parent field guide for this element.
- ReferenceThe laws of incentives
Goodhart, Campbell, and the Cobra Effect.
- EssayThe Perverse Incentives Hiding in Your KPIs
The measurement failure mode for this element.
- CourseIncentives 101
The free ten-part primer on reading a payoff structure.
- ReferenceThe incentive glossary
Definitions for every mental model, bias, and fallacy in the corpus.
- ReferenceThe Periodic Table of Human Behavior
The full 1,267-element map this page belongs to.
Questions about Goodhart's Law
- What is Goodhart's Law?
- Goodhart's Law is when a measure becomes a target, it ceases to be a good measure. It sits in the Incentives dimension (INC) of the Human Behavior Taxonomy™ as element HBT-INC-0137, within the Universal Pattern Perverse Pattern family. The core principle: when a measure becomes a target, it ceases to be a good measure. In incentive terms, it matters because it changes the payoff people perceive before they choose — which means it can be designed for, or exploited.
- What is an example of Goodhart's Law?
- Every KPI eventually corrodes if attached to comp without offsetting metrics. The Incentives Lab catalogs everyday, organizational, and historical instances of this element on its Human Behavior Taxonomy™ page (HBT-INC-0137).
- How is Goodhart's Law exploited?
- Every KPI eventually corrodes if attached to comp without offsetting metrics.
- How do you design around Goodhart's Law?
- Pair every metric with a counter-metric. Rotate KPIs. Audit gamification.
- Which behavioral dimension does Goodhart's Law belong to?
- Goodhart's Law is classified in the Incentives dimension (INC) of the Human Behavior Taxonomy™, family "Universal Pattern Perverse Pattern", class "Perverse Incentive". Its permanent identifier is HBT-INC-0137 and its evidence grade is C.