Goodhart’s Law

Never seen it formalised before, though I’ve expressed it so many times. Posted as David Gurteen’s quote of the day with the source identified by @BrianSJ.

When a measure becomes a target,
it ceases to be a good measure.

The basic reason why MBO is doomed; the antidote to “if you can’t measure, you can’t manage”. And it’s really an alternative expression of Douglas Bader’s adage “Rules are for the guidance of wise men, and the enslavement of fools”. (In economics, a variation on Campbell’s Law and Lucas Critique – follow the wikipedia links from here.)

In the latter form it is more obvious how this is game theory. Games have rules, if you introduce new benefits / sanctions associated with one of the rules – it’s a game changer. The “artificial” benefit / sanction becomes part of the game, no longer just a rule, but an object in its own right. If you treat people like juveniles, they’ll behave like juveniles. Careful what you objectify. Careful what you wish for. The underlying adage is probably as old as humanity and cod-psychology.

Governance. Object reification in game theory.

Here a case where it was literally applicable to a game, a sport, football. A Terry’ble Decision.

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