Introduction
Perhaps no other principle in contemporary policy debates has achieved the level of widespread acceptance as the precautionary principle. This principle is called upon in various areas of public policy, such as environmental law, public health law, food safety law, and international treaties, and encourages policymakers to be cautious in the face of uncertainty that has the potential to produce serious harm even in the absence of scientific consensus. In his book, Laws of Fear: Beyond the Precautionary Principle, the legal scholar Cass R. Sunstein provides a careful and meticulously constructed criticism on the widely accepted notion of the precautionary principle. With the help of ideas borrowed from cognitive psychology, economics, and political philosophy, Sunstein shows that the precautionary principle is not only impracticable but also incoherent and suggests that policymakers must be more careful in conducting a cost-benefit analysis. This brief but intellectually rich book, originally presented as the Seeley Lectures at Cambridge University, shows Sunstein at his usual high level of clarity and argumentative precision. It is a work that must be considered even when it challenges dissent and is perhaps the most comprehensive criticism on the precautionary principle in the literature.
The Core Argument: Paralysis and Incoherence
Sunstein’s basic argument is that if the precautionary principle is actually taken into consideration, it necessarily undermines itself. This is because the precautionary principle asserts that if certain activities present certain threats of harm, precautionary action must still be taken even if certain cause-and-effect relationships are not well scientifically established. While at first glance the precautionary principle appears to be common sense, Sunstein shows that in nearly all real-world scenarios, action and inaction will both present certain risks. For example, if regulators bar the use of a certain pesticide that is potentially harmful, not only does that potentially create certain harms, but it might also create certain other harms, such as the spread of disease, diminished agricultural productivity, or economic consequences that in turn create public health consequences.
This, Sunstein argues, makes the principle either paralysing, in that it cannot be applied universally, or arbitrary, in that the application of the principle reveals value judgments that are not made explicit. In a well-researched set of case studies on genetically modified organisms, nuclear power, climate change, and pharmaceuticals, Sunstein illustrates the way in which the precautionary principle is often applied inconsistently: precaution is cited to prevent the development of some technology, but the costs of not developing that technology are not addressed.
Behavioural Roots: Probability Neglect and the Available Heuristic
One of the book’s most valuable contributions is its engagement with behavioral science. Sunstein uses a body of research in cognitive psychology to understand why the precautionary principle has such strong political pull even when it is unsuccessful as a rational decision-making tool. He discusses two specific phenomena: the availability heuristic, in which individuals judge the probability of an event by how easily examples of it come to mind, as opposed to statistical evidence; and probability neglect, in which individuals strong emotional reactions to worst-case scenarios lead them to focus on the severity of a given harm without regard to its probability.
These cognitive biases, according to Sunstein, are what underlie precautionary reasoning, even though it is not a reliable one. The precautionary principle, he argues, codifies these biases. Where risks are salient, vivid, and involve involuntary or unfamiliar risks, such as those of chemicals, technologies, or radiation, the public, as well as policymakers, tend to overestimate risks. The precautionary principle, far from being a corrective, institutionalizes these biases. While Sunstein does not wish to be seen as writing off public concerns as irrational, he recognizes that emotions are frequently a legitimate and epistemically relevant input into moral judgments. However, he is of the view that emotions cannot be allowed to be the sole basis of policy, especially when there is a systematic distortion in risk assessment.
The Proposed Alternative: Proportionate Cost-Benefit Analysis
Instead of precautionary reasoning, Sunstein promotes a cost-benefit approach in which all important risks, including regulatory risks, are quantitatively weighed against one another. But this does not mean that Sunstein thinks that every decision can be reduced to a cost-benefit calculation. He is alive to the difficulties of assigning a dollar value to human life, to ecological damage, and to irreversible damage. He also agrees that catastrophic risks ought to be treated specially, because the potential cost of being wrong about a low-probability catastrophe may justify a kind of regulatory conservatism.
The system that Sunstein is proposing is not a technocratic system in any cold or calculating sense. He acknowledges the importance of democratic deliberation, equity, and the importance of the burden of risks borne by individuals against their will. What he is opposing is the substitution of emotional significance for facts and the use of the precautionary principle as a basis for refusing any comparative analysis. On this point, his case is unassailable: the challenges of cost-benefit analysis are better met by reforming the system than by discarding rational analysis altogether in favor of a principle that cannot make comparative judgments between competing risks.
Critical Evaluation
Laws of Fear is an intellectually powerful book, but it is not without its weaknesses. For example, critics from the domain of environmental law and political philosophy have argued that Sunstein’s definition of the precautionary principle is focused on the weakest formulation of the precautionary principle. In fact, stronger versions of the precautionary principle, such as that articulated in international environmental law, do not require that action on both sides of the risk equation be risk-free. Instead, it simply asserts that in the face of scientific uncertainty, the burden of proof should rest on those advocating an activity that is potentially harmful. This is clearly not as strong a claim as Sunstein makes against it, nor is it necessarily refuted by the existence of risks on both sides of the equation.
There is also a tension between Sunstein’s faith in the results of cost-benefit analysis from a technocratic point of view and Sunstein’s acknowledgment of the cognitive limitations of the people doing the cost-benefit analysis. If the cognitive limitations of the “lay public” lead to availability phenomena and the neglect of probabilities, it is not obvious that regulators and economists are any different. The issue of which group gets to define the framing of the cost-benefit analysis is not discussed as much as it might be. But these are all objections that deal with the book on its own terms, and they do not diminish the basic contribution that Sunstein is making.
Conclusion
Laws of Fear is a book that is absolutely necessary reading for anyone involved in the theory and practice of risk regulation. Sunstein does not wish to deny the value of caution or regulation; rather, he wishes to ensure that precaution is itself rational, transparent, and comparative if it is to serve the public good rather than simply to reinforce the fears that at any particular time are most politically powerful. In an age of increasing technological uncertainty, from artificial intelligence to synthetic biology to climate change tipping points, the problem of how democratic societies reason about low-probability but high-consequence risks has never been more pressing. Sunstein’s engagement with that problem is as relevant today as it was when it was first written.
References
Cass R. Sunstein, Beyond the Precautionary Principle, 151 U. Pa. L. Rev. 1003 (2003).
Cass R. Sunstein, Beyond the Precautionary Principle (John M. Olin Program in Law & Econ., Working Paper No. 149, 2003).