Noise: rigid rules drive discretion underground, where "there will be noise, but no one will hear it"; agent rules need monitoring of what agents actually do.

The claim

Kahneman, Sibony and Sunstein warn that rules imposed to cut noise can relocate it out of sight, as with prosecutors avoiding three-strikes charges: "Whenever a public or private institution tries to control noise through firm rules, it must always be alert to the possibility that the rules will simply drive discretion underground." and "When such things happen, there will be noise, but no one will hear it." For agents the underground is unlogged reasoning and unrecorded choices about what to bring before the rule at all. A collective that adopts rules for its agents has to monitor outcomes, not compliance, and treat re-emerging variance as a sign the rule is being worked around. Inference beyond the quotes is Leo's.