A tax that made a dog’s tail a liability
Corsica’s dog levy turned a visible feature of an animal into a reason for owners to pay. That created a crude but powerful incentive: if removing the tail meant the dog no longer counted as taxable, cutting it off could save money.
The response exposed a basic weakness in the tax’s design. Rather than changing who owned a dog or how much it cost to keep one, the rule made payment hinge on a part of the animal that owners could remove. The tax shifted its cost onto the dog’s body.
When avoidance meant an irreversible cut
For an owner weighing a recurring levy against a one-time action, mutilation could appear financially advantageous. But unlike an ordinary fee, the consequence of avoiding this one was permanent for the animal. A policy intended to collect money therefore gave owners a reason to inflict physical harm to escape it.
The episode is a stark example of how people adapt to the incentives a rule creates—even when the adaptation defeats the rule’s apparent purpose. In Corsica, the measure did not merely determine whether an owner paid: it could determine whether a dog kept its tail.
