Charles Goodhart once said, "When a measure becomes a target, it ceases to be a good measure." Sounds like a clever play on words, but it's actually a warning about how humans, systems, and incentives work.
Let's break it down like we're trying to explain it to a curious high schooler.
Measures Are Just Maps
Imagine you're hiking in the Drakensberg with a map. The map helps you navigate, but the map is not the mountain. If you start worshipping the map instead of looking at the mountain itself, you'll get lost.
A measure, like "sales per month" or "test scores", is a map. It's a simplified picture of something more complicated: customer satisfaction, student learning, or organisational health.
As long as we use the measure as a guide, it's useful. But once we say, "This number must go up, or else," we stop caring about the mountain and start redrawing the map to look nice.
Why It Breaks
Humans are clever. Give them a target, and they'll find the shortest path, even if that path doesn't lead to the original goal.
- Schools: Instead of cultivating curiosity, teachers teach exam tricks because pass rate is the target.
- Hospitals: To hit waiting-time targets, patients are shuffled around or discharged early.
- Companies: To hit quarterly sales, reps oversell products and leave customers angry.
The metric goes up, but the system gets worse. That's Goodhart's law in action.
The Physics of Incentives
Think of it like pressure in a pipe. The more force you apply to one side, the more leaks spring up elsewhere. Push hard on one metric, and energy leaks out in the form of corner-cutting, manipulation, or unintended consequences.
That's not because people are evil. It’s because systems adapt. And if the system adapts to the number instead of the thing the number represents, the number stops being meaningful.
How To Outsmart Goodhart
So what do you do? Refuse to measure? Of course not. Measurement is the only way to learn. But you need to treat metrics like tools, not gods.
- Use many measures, not one. A dashboard of gauges is harder to game than a single speedometer.
- Pair numbers with stories. If customer churn is down, why is it down? Listen before you celebrate.
- Focus on behaviour, not just outcomes. Reward the practice of calling customers back, not just the revenue number.
- Review and rotate. Today's useful KPI becomes tomorrow's loophole. Refresh your indicators regularly.
The Deeper Lesson
Goodhart's Law isn't just about business. It's a reminder that reality is richer than the symbols we invent to capture it. Maps aren't mountains. Scores aren't knowledge. Likes aren't love.
The trick is to stay awake: keep checking if your measures still measure what you think they measure. If not, adjust.
Otherwise, you'll be like a hiker staring proudly at a perfect map, while walking straight off a cliff.
That's Goodhart's law in plain terms: Don't confuse the scoreboard for the game.
