… is from page 33 of the late, great Paul Heyne’s 1993 essay “Economics, Ethics, and Ecology,” which is chapter 2 in Taking the Environment Seriously  (Roger E. Meiners and Bruce Yandle, eds., 1993) (original emphasis):
Since judgments about efficiency presuppose judgments as to who shall have which rights, economists who employ efficiency criteria are implicitly making use of a theory of rights. Does economics have anything useful to say about the rights that people ought to have?
One thing economists can say with some confidence is that clear and stable rights promote more effective cooperation than rights which are vague and subject to unpredictable alteration. Given that voluntary exchange increases the value of resources and that clear and stable property rights (and other “rules of the game”) facilitate voluntary exchange, economists can construct a strong argument in favor of clear and stable property rights. In doing so, they are also supporting a particular conception of justice, one associated with what has come to be known as “the rule of law.”
“Unconstitutional by reason of vagueness” is a sound judicial principle for assessing legislation, because vague laws grant arbitrary power to enforcement authorities. The liberty of the citizen disappears in the presence of arbitrary government power.