A few years ago, I wrote about one of the best pieces of advice I got from my old boss, Dao Nguyen:
I’ve learned a lot from Dao over the years. But one sentence in there really drives home Dao’s biggest message: “Anyone who just optimizes to one metric is going to eventually have a problem.”
What we’ve learned with newsletters is that there is no “silver bullet” metric. If you try to optimize your email for open rate, you’ll try to game the system with headlines that entice subscribers to click. (Case in point: “You’re Fired.”) But if you overpromise and underdeliver, you’ll lose subscribers in the long run. If you try to optimize for clicks, you’ll use bold colors and buttons. It’ll work well at first — but readers will learn to tune them out. There are dozens of other metrics out there for email. And what Dao’s taught me is true: If you focus all of your energy on a single metric, in the long run, you’ll fail.
What I’ve recently learned is that there’s actually a law that explains exactly this! It’s called Goodhart’s Law, and it has one key rule: “When a measure becomes a target, it ceases to be a good measure.” Or as NPR’s Planet Money put it in a fantastic recent episode: “Be careful what you measure because your employees are going to make it happen.” They may break some rules to hit their assigned goal. They may actually make things worse, from a big picture perspective, to reach their target. But Goodhart’s Law suggests that if they have that silver bullet metric in mind, they will find a way to hit it.
Listen to the whole “Planet Money” episode — it’s a fantastic look into how things can go wrong at the office.
———
That photo, of an old GE voltmeter, comes via Thomas Kelley and Unsplash.