Why Going to the Gym Three Times a Week Doesn’t Mean You’re Fit (and Other Goodhart’s Law Fallacies)

Imagine this: you decide it’s time to live a healthier lifestyle and resolve to go to the gym three times a week. Once there, however, you spend more time chatting with your buddy than working up a sweat. You lift a weight every now and then, but really intense exercise? Still, you went to the gym three times a week, so your mission is accomplished, right? Well, not really… This is a perfect example of the phenomenon Goodhart’s Law.

What is Goodhart’s Law?

Goodhart’s Law states: “When a measurable factor becomes the goal in itself, it loses its value as a measurable factor.” In other words, if you fixate on a single number or goal, you often lose sight of what you really want to achieve (Goodhart, 1975). A striking example is when a company’s success is measured by sales figures and employees are rewarded for them, without taking customer satisfaction or product quality into account. The result: high sales figures, but dissatisfied customers.

The danger of misplaced focus

Setting goals is valuable in and of itself. They provide direction, help you stay focused, and allow you to track your progress. Goals motivate us to take action and give us a sense of progress (Locke & Latham, 2015). However, there is a danger in fixating on a single goal to measure success. If you’re only concerned with the number of hours you spend at the gym or the number of products you sell, you can easily lose sight of important factors such as efficiency, quality, or (customer) satisfaction. And does that measurement even serve the actual end goal?

Examples of Goodhart’s Law in action

You see Goodhart’s Law popping up everywhere. Consider, for example:

• The Speedy Pizza Delivery Service: A pizzeria introduces a bonus for delivery drivers who deliver their pizzas within 30 minutes. The result? Delivery drivers racing through the city like maniacs and pizzas arriving upside down.
• The Library Marathon: A university rewards students who visit the library most frequently. The result? Students who check in to sleep, watch Netflix, or even just drop by briefly to clock in, without actually studying.
• The tidying illusion: Parents tell their children to clean up their rooms and promise a reward if everything is neat. What do the children do? They just shove everything under the bed or into the closet. It looks tidy, but when you open that closet door, you’re buried under an avalanche of toys and clothes. They’ve achieved their goal (a tidy room), but not in the way their parents had in mind.
• But also, universities that manipulate statistics to climb higher in the rankings, causing the true value of education to take a back seat.

All these examples show that while you may achieve a goal (library hours, revenue targets, athletic performance), you ultimately pay a price: missed learning opportunities, dissatisfied customers, or a loss of personal integrity. That is the tragedy of Goodhart’s Law: even when you win, you lose. 

Goodhart’s Law in Our Daily Work

Goodhart’s Law also has an impact on the field of Conversion Rate Optimization (CRO). A company whose primary goal is to increase the conversion rate runs the risk of overlooking other important aspects of the customer journey. Teams focus on short-term tactics, such as using aggressive promotions or misleading tactics (dark patterns), without giving any thought to customer satisfaction or long-term customer relationships.

Successful website optimization isn’t about improving a single page or a single metric. It’s about understanding and improving the entire customer journey. Only by taking a holistic approach can companies grow without negatively impacting their customers or their brand. We're here to help Please continue here! 

Finding a balance

How can you avoid falling victim to Goodhart’s Law? The answer lies in setting the right goals, combined with a broad perspective. Yes, measurement is important. It gives us insight into our progress and performance. But no measurement is perfect. It is crucial to consider qualitative factors alongside quantitative ones and to maintain a broader view of the ultimate goal.

Whether it’s about exercising more, boosting sales, or optimizing a website: let’s make sure we don’t get bogged down in chasing a single number, but keep our eyes on the things that really matter.

Conclusion

Goodhart’s Law reminds us that setting goals and measuring progress is important, but it’s not the only thing that matters. When the measurement itself becomes the goal, we lose sight of why we set the goal in the first place. So keep looking at the bigger picture and make sure you not only hit the number but also preserve the value it represents.

References:

• Goodhart, C. (1975). “Problems of Monetary Management: The U.K. Experience”. In Courakis, Anthony S. (ed.). Inflation, Depression, and Economic Policy in the West. Totowa, New Jersey: Barnes & Noble Books.
• Locke, E., & Latham, G. (2015). Goal-setting theory. In Organizational Behavior 1 (pp. 159–183). Routledge.