In order to protect the environment the Precautionary Approach is widely applied: fundamentally, where there are potentially grave or irreversible threats, lack of full scientific certainty shall not be used as a reason for postponing cost-effective action.
The main difference is in how precaution should be exercised in practice. This basis for precautionary principle in many conventions and treaties requires differentiating them from those that are legally binding and those that are not. An early example of legal precaution is Justinian’s statement, in 527AD, that “the maxims of the law are to live honestly, to cause no harm unto others, and to give everyone his due”. Today, the forms of the precautionary principle generally require ranking of choices based on either a full risk-cost-benefit balancing or some accounting for the costs or risks, or both, but one should also consider, depending on the jurisdiction, factors that go beyond the confines of cost–benefit analysis. Legal principles are generally unenforceable as such, although modern legislation accords them a positive and guiding force; preambles and principles are statements of general legal intent and thus lack the specificity required for enforcement. On the other hand, certain enunciations of the precautionary principle are a constitutional command, as in the EU.
Precautionary principles should be differentiated from other principles of precaution, such as zero or significant risk because the former are part of statutory law, while precautionary principles are often constitutional. All however reflect varying levels of public policy, often resulting in secondary legislation that can err on the side of uniformity and ease of use by adopting conjectural defaults. Precautionary principles formulate a moral justification for acting when a hazard can potentially cause severe consequences and its causation is uncertain. This moral justification can result in a suboptimal choice: consequences that are more adverse have been known to occur after implementation of a precautionary choice.Yet the concern is that anticipatory actions and erring on the side of caution are necessary in choices that affect occupational or public hazards. In some of those principles, the magnitude or the severity of the potential consequences leads to disregarding their probabilities and the uncertainty in the causal connection between them and the hazard. Bans characterise these choices. Others believe in the proposition that precautionary decisions and choices must be guided by balancing risks, costs, and benefits, as well as being characterised by a specific level of legally demonstrable causation.
The repeated lesson, still only partially included in much political discussion, is that precautionary choices thought to prevent hazards when they are implemented, are later found to cause unanticipated harm. If that unanticipated harm could have been predicted, the failure to have done so is inexcusable in the sense that acting on a conjectured danger, justified by a legal maxim, is unfair – because it redirects scarce resources from more valuable societal investments.
Yet, not acting by postponing preventive action, because of large uncertainties surrounding the severity of the hazard, can increase the magnitude of those consequences. Thus the dilemma, should society wait until uncertainties are sufficiently resolved to trigger regulatory action, or act precipitously on a conjecture? The corollary question is; What is sufficient evidence?
There is a simple rule that is specific to uncertain hazards: the assessment and selection of the preferred choice from the set of choices is based on scientific analyses of these choices, given the full – and thus avoiding simplifying assumptions or practical shortcuts – state of knowledge about the hazard. Each choice, consequence, probability of occurring, and so on is assessed through risk-cost-benefit balancing; the idea is to inform and guide decision makers and stakeholders, not command them to commit to a specific action. The justification of the final choice in the public interest, a matter of public policy, must account for factors that cannot be directly included in the risk-cost-benefit balancing. In the EU, for example, having to account for the economic and social development of the community as a whole, as per Art. 134r(3) of the Treaty of Maastricht can require analyses that extend beyond the confines of a choice-specific balancing. The risk-cost-benefit analyses are essential because they account for uncertainty, causation, the value of new information and the cost of gathering it, and the utility of the payoffs associated with each option open to the decision maker. In terms of how to analyse those actions, balancing criteria such as the maximisation of the expected discounted values of the payoffs, can guide the selection of the optimal (relative to the criterion adopted) act by identifying it. Those analyses are transparent, replicable, and testable via a number of methods, including simulations. Their extent can go beyond microeconomic consideration to include macroeconomic ones. There are costs of either action or inaction to society; nonetheless, the magnitude of the stakes justifies formal analysis of risky choices. However, conducting formal analyses is also costly. These costs include having to deal with: complex mathematical and statistical issues, data needs and their availability, and several forms of uncertainty and variability. In the end, the results from formal analysis are constructive and meant to inform policy-makers. Although the analyses are formal and thus independently replicable, those analyses are not normative.
Assessing and implementing actions to limit exposure to the hazardous situation and thus reduce risk and monitoring risky choices under a precautionary principle are the explicit results of legislative fiat that are costly to society. That is, it is possible that the improperly justified allocation under a precautionary principle would divert some scarce resources to pay for an action that is much less protective than its next best alternative, as measured by the opportunity cost of the action not taken.
When the magnitude of the consequences and the probabilities are both large, quick action becomes imperative.
Precautionary principles argue for both circumspection and prevention when the magnitude of the potential adverse event is severe, but its probability is relatively small. Arguing for costly action when the causes of the adverse event are either poorly understood or conjectural is unlikely to result in an equitable distribution of risks and benefits, if an action developed on such basis is taken. When the expected loss of a choice is small, some can argue against taking immediate precautionary action if the magnitude of the expected value is smaller than some legal minimum. Others look at the magnitude and severity of the probable outcome, but keep probability and magnitude separate and do not multiply them, thus arguing for action even when the probability is small but the magnitude of the adverse consequences is large. These alternative situations reinforce the suggestions that, regardless of their wording, the enunciation of the precautionary principle should contain specific guidance on the strength of the scientific evidence and the explicit recognition of time-dependent changes in scientific information.
This article is an edited version of
an entry in the “Encyclopedia of Quantitative Risk Analysis and
Assessment”, Copyright © 2008 John Wiley & Sons Ltd. Used by
permission.
