Passage A

Law enforcement agencies can effectively nullify particular laws, or particular applications of law, simply by declining to prosecute violators. This power appears to be exercised frequently and I attempt here to explain why.

Rules of law are almost always overinclusive: read literally, they forbid some conduct that the legislature that formulated the rule did not want to forbid. The costs of precisely tailoring a rule to the conduct intended to be forbidden would be prohibitive given the limitations of human foresight and the inherent ambiguities of language. The more particularly the legislature tries to describe the forbidden conduct, the more loopholes it will create. Enforcing an overinclusive rule to the letter could impose very heavy social costs. The effect would be like punishing an innocent person in order to reduce the probability of acquitting a guilty one. Of course, the danger of punishing the innocent is not a decisive blow against the use of a particular method of law enforcement; the danger must be traded off against the costs of alternative methods that would reduce it. But there is a technique—discretionary nonenforcement—by which the costs of overinclusion can be reduced without a corresponding increase in underinclusion (loopholes).

Of course, allowing discretionary nonenforcement does not determine the principle by which the law enforcement agency will select its cases. Conceivably the agency could concentrate its resources on those areas of conduct that had been brought inadvertently within the scope of the rule. But this seems unlikely. Capricious enforcement is not unknown (or even rare) but it does not appear to be the central tendency since legislative oversight assures that the agency does not stray too far from the intended, as distinct from the enacted, regulation being enforced.

Passage B

The newspaper reported that 231,000 water customers in the city are late paying their bills—some by months, others by decades. In all, these water delinquents owe the city more than $625 million in overdue bills and penalties. So officials are planning to selectively cut the water to a few residences with outstanding bills to show that they are serious about collecting those debts. Officials plan to target only high-income neighborhoods, to make examples of a few privileged residents who will be in no position to complain since they were caught stiffing the system.

But property owners are responsible for water bills. So why not just do what every other property-related creditor or tax authority does—attach a lien to the property? The money owed would automatically be available whenever a property was sold, and the threat of negative credit implications would be a powerful incentive to keep current with one's water obligations.

Well, here's an answer: a loophole prohibits debts other than taxes from being subject to liens by the city, and, technically, water charges are not taxes. But if the problem is with the law, then why not change the law? Wouldn't that be easier, and politically smarter, than shutting off people's water?