the tyranny of the measurable

When a measure becomes a target, it ceases to be a good measure. The line is credited to Charles Goodhart, a Bank of England economist writing in 1975 about monetary policy, though the version everyone quotes was actually Marilyn Strathern’s, an anthropologist compressing him two decades later; and the fact that a law about central banking needed an anthropologist to finish it should tell you something about where it was always headed.

Goodhart had noticed a narrow thing: whenever the Bank picked a statistical indicator and steered by it, the indicator promptly stopped indicating. The relationship it had once tracked dissolved on contact with intention.

He thought he was describing a problem in economics. He was describing, you and I can now see, a problem in being alive after 1975.

Here is the mechanism: a measure is a proxy; it stands in for something you actually care about but cannot observe directly.

Grades stand in for learning.

Followers stand in for influence.

Steps stand in for health, KPIs for value, citations for insight, matches for desirability.

The proxy works precisely because, in the unobserved wild, it correlates with the real thing; students who learn tend to score well, healthy people tend to move.

But the moment you attach consequences to the proxy, you have changed the ecosystem in which the correlation evolved. You have created a reason to produce the number without the thing, and producing the number without the thing is always cheaper, because the thing was the expensive part; that was why you needed a proxy in the first place.

The measure does not just fail. It is hollowed out and worn as a costume; and the better the incentive, the faster the hollowing.

Donald Campbell, a psychologist, got there independently and said it with less English restraint: the more any quantitative indicator is used for decision-making, the more it will corrupt, and the more it will corrupt the very process it was meant to monitor. Note the second clause, reader, because it is the one people miss. The number does not just become a lie; it reaches back and deforms the reality it was supposed to describe.

You know the case studies because you have lived inside them. Grades became targets, and so we got the student who can extract an A from a course the way a locksmith extracts a click from a tumbler, having brushed against no idea in the process; not a cheat, mind you, but an honest optimiser of the wrong function, and the institution rewards her because the institution can only see the function.

Steps became a target, and there are now people (admittedly myself included at one point) who pace hotel rooms at 11:40 p.m., not for their heart but for a ring on a watch; the proxy has fully detached and floats free, worshipped in its own right.

The KPI became a target and gave us the support desk that closes your ticket unresolved, because “tickets closed” is counted and “problems solved” is not; the hospital that games its mortality statistics by declining the sickest patients; the police force that reclassifies crimes to hit a reduction target, so that the number improves while the street does not. In each case, notice, no one is villainous.

Everyone is responding rationally to the scoreboard they were handed; which is the whole horror of it, that Goodhart’s law requires no bad actors, only actors.

And then there is the more persistent version you carry in your pocket. The follower count was a proxy for having something to say; it became a target, and now there exists an entire profession of saying things in order to move the count, which is the correlation running backward, the tail wagging the dog. The like was a proxy for resonance; made a target, it bred a grammar of resonance-shaped content, engineered to trip the sensor the way certain flowers evolved to look like female wasps.

Dating applications completed the sequence with almost laboratory cleanness: they took the unmeasurable thing, whatever it is that happens between two people in a room, and proxied it with photographs and swipe-rates; and the swipe-rate became a target; and so people now curate themselves toward the metric, angles and captions and calculated scarcity, becoming steadily more optimised for selection and, by the same operation, less like anyone you could live life with. The profile improves as the person recedes.

That sentence is Goodhart’s law entire, and you have watched it happen to acquaintances, and possibly, be honest, in the mirror.

Now, the obvious rejoinder, and it deserves its hearing: measurement is not optional. James C. Scott, in Seeing Like a State, showed why institutions must make the world legible, must flatten forests into board-feet and villages into tax rolls, because a state, a company, a platform can only act on what it can count.

The rejoinder is right that we cannot govern without counting; the rejoinder forgets that the map’s omissions do not stay omitted. Optimize the map hard enough and the territory reorganises itself to match, shedding, one by one, every property the map left out; and the properties the map leaves out are, reliably, the ones that were hardest to fake, which are the ones that mattered.

I wrote here recently that the purpose of a system is what it does; Goodhart supplies the corollary, and the corollary is worse. Tell a system what you are measuring, and what it does will converge on the measurement; so the metric does not describe the system’s purpose, but it becomes the system, ratified by every promotion and payout, until the org chart is full of people pursuing a number that no longer means what its founders meant by it, and could not say when the meaning left.

Institutions, at least, sometimes audit themselves.

The self does not; and the self is now instrumented as no self has ever been, with sleep scored, attention tracked, friendships tallied, and the whole interior fitted with sensors. Each and every sensor is an invitation for the correlation to invert, for you to begin producing readings instead of living the life the readings once reflected.

The danger, reader, is not that you will be measured by others; you have always been measured by others, and you have defences against them in irony and privacy and contempt.

The danger is the day you adopt the proxy as your own inner criterion; the day the question “did I write something true?” is replaced by “did it perform?”. The measurable does not defeat the unmeasurable in argument. It defeats it in latency. Feedback that comes fast and denominated will always outshout feedback that comes slow and mute, and so, without ever choosing to, you begin steering by the instruments and calling it navigation; and the parts of your life that emit no data, begin to feel like they are not happening.

They are the only parts that are happening.

That is the position I want to leave you with. Whatever in your life can be counted has, by now, been targeted, by a platform, an employer, or your own instrumented conscience; and whatever has been targeted has already begun its drift from meaning, on a schedule set by the strength of the incentive.

The uncounted remainder, the residue that fits in no dashboard, is therefore not the soft or sentimental portion of your existence; it is the portion still capable of meaning anything, precisely because nothing is paying it to lie.

Guard it accordingly.

Do not fix this by measuring better; there is no better, the law eats every proxy in the end.

Fix it by keeping some things illegible on purpose.

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