--- title: "Everyone Hit the Target" description: "Rat tails, sales targets, waiting times. Reward a number and it will climb. The thing it stood for may not." author: "Harry Floyd" publication: "The Durability Curve" canonical: "https://durabilitycurve.com/blog/everyone-hit-the-target/" date: "2026-10-04" series: "THE BLUEPRINT" format: "markdown mirror of the canonical HTML page; figures are named, not embedded" --- # Everyone Hit the Target *Rat tails, sales targets, waiting times. Reward a number and it will climb. The thing it stood for may not.* By Harry Floyd · 2026-10-04 · canonical: https://durabilitycurve.com/blog/everyone-hit-the-target/ In 1902, the French administration running Hanoi had a rat problem. The city's new sewers, the pride of its colonial engineering, had turned out to suit the rats perfectly, and the rats carried plague. So the authorities reached for what looked like a clean solution. They put a bounty on rats. Anyone who brought in a rat's tail got a small payment, and the city would buy its way to fewer rats. The tails came in by the thousand. Then officials started noticing something out in the streets: rats, alive and healthy, running about with no tails. People had worked out that only the tail was paid for, and a rat let go would breed more tails. So they caught rats, cut off the tails and let the rats go. The more enterprising skipped the streets altogether and set up rat farms on the edge of the city. The bounty was paid, the tally of tails climbed, and the rat problem did not improve. The administration's own conclusion, once it understood what it had built, was that the scheme was breeding more rats than it caught.[^1] The mistake is easy to name once you see it, and easy to make. What the city paid for was a stand-in, a tail handed over a counter, and the cheapest way to produce that stand-in had nothing to do with the goal of fewer rats. Whatever you actually care about tends to be hard to measure head-on, so you reach for a number that moves with it, and that number is an honest signal only for as long as nobody is pushing on it. Attach a reward and you lean on it with your whole weight, and the two come apart the instant moving the number is cheaper than delivering the real thing. The cruel part is that the number keeps climbing. It looks like triumph, right up until someone checks the thing it was supposed to stand for and finds that it never moved, or quietly got worse. [Figure: The reward cannot tell the two roads apart, so the shortcut wins.] You do not have to go back to colonial Hanoi for this. When Wells Fargo set its staff aggressive targets for how many products each household held, the staff hit those targets by opening millions of accounts that customers had never asked for and did not know existed. The measure, products per household, looked spectacular. The thing it was meant to stand in for, customers happily choosing more of the bank's services, had been faked account by account, and when it came to light it cost the bank billions and a great deal of its name.[^2] [Figure: The dashboard says 100%. What it stood for got worse.] The same shape appears wherever a clock is the target. Give hospitals a four-hour limit on emergency waits and the four hours quietly become the job. In England, some hospitals kept patients waiting in ambulances queued outside the doors, where the four-hour clock had not yet started, until staff were sure they could deal with each one in time. Waits did fall, but the official figures ran well ahead of what patients themselves reported.[^3] Once you have the shape you find it wherever a number with a shortcut carries a reward or a punishment. Put schools in a league table and some will teach to the test, because the test is what gets counted. If there is a cheap way to move the count, paying for it gets you more of the count and less of what it was counting. What you can carry away from all this is a single question, put to any number someone holds up as proof that things are going well. What is the cheapest way to move this number, the cheapest way that has nothing to do with the real work? If such a path exists, and anyone is rewarded for the number going up, assume it has already been found. A figure that has become a target should send your attention straight past it, to [the thing it was only ever standing in for](https://durabilitycurve.com/blog/the-evaluation-inversion/), which is what you wanted to know in the first place. None of this means you should throw the numbers away. You cannot run a hospital or a school or a company on feeling alone, and a measure that no one is gaming tells you something real. The trap is narrow and specific. It springs when a single number that can be moved on its own is handed a reward, so that hitting the number becomes the point and reaching the goal becomes optional. Everyone hit the target. That was the problem. [^1]: Michael G. Vann, [Of Rats, Rice, and Race: The Great Hanoi Rat Massacre, an Episode in French Colonial History](https://muse.jhu.edu/article/42110), French Colonial History 4 (2003): 191–203. Vann documents the tail bounty, the cut-and-release of live rats, and the rat farms from the colonial archive; the administration concluded the scheme was increasing the number of rats in the city. [^2]: Consumer Financial Protection Bureau, [Consumer Financial Protection Bureau Fines Wells Fargo $100 Million for Widespread Illegal Practice of Secretly Opening Unauthorized Accounts](https://www.consumerfinance.gov/archive/newsroom/consumer-financial-protection-bureau-fines-wells-fargo-100-million-widespread-illegal-practice-secretly-opening-unauthorized-accounts/) (8 September 2016). The 2016 penalties totalled $185 million; a later Justice Department and SEC settlement in 2020 reached $3 billion. [^3]: Gwyn Bevan and Christopher Hood, [What's Measured Is What Matters: Targets and Gaming in the English Public Health Care System](https://doi.org/10.1111/j.1467-9299.2006.00600.x), Public Administration 84, no. 3 (2006): 517–538. In 2002/03, 139 of 158 acute trusts officially reported ninety per cent of patients seen within four hours, but only sixty-nine per cent of surveyed patients said they had been; by 2004/05 the figures were ninety-six and seventy-seven per cent.