Iowa Law Review
Scholars and lower courts have traditionally operated under the belief that cases involving direct tradeoffs between free speech and national security call for the application of straightforward cost-benefit analysis. But the Supreme Court has refused to adhere to this approach, instead deciding difficult liberty-versus-security questions with reference to a "probability threshold"--a doctrinal floor defining how likely a potential threat must be in order to register in the constitutional calculus. This doctrinal innovation has served as a necessary corrective to what would otherwise be the systematic overestimation of speech-based threats driven by the interaction of two factors. First, distinct informational asymmetries favor the government, the putative censor. Second, courts and other lay risk analysts-through the exercise of bounded rationality-tend to overstate very low-probability, highly emotionally salient dangers.
Jonathan Masur, "Probability Thresholds," 92 Iowa Law Review 1293 (2007).