The Precautionary Principle: A Plea for Proportionality

by on February 7, 2022 · 0 comments

Gabrielle Bauer, a Toronto-based medical writer, has just published one of the most concise explanations of what’s wrong with the precautionary principle that I have ever read. The precautionary principle, you will recall, generally refers to public policies that limit or even prohibit trial-and-error experimentation and risk-taking. Innovations are restricted until their creators can prove that they will not cause any harms or disruptions. In an essay for The New Atlantis entitled, “Danger: Caution Ahead,” Bauer uses the world’s recent experiences with COVID lockdowns as the backdrop for how society can sometimes take extreme caution too far, and create more serious dangers in the process. “The phrase ‘abundance of caution’ captures the precautionary principle in a more literary way,” Bauer notes. Indeed, another way to look at it is through the prism of the old saying, “better to be safe than sorry.” The problem, she correctly observes, is that, “extreme caution comes at a cost.” This is exactly right and it points to the profound trade-offs associated with precautionary principle thinking in practice.

In my own writing about the problems associated with the precautionary principle (see list of essays at bottom), I often like to paraphrase an ancient nugget of wisdom from St. Thomas Aquinas, who once noted in his Summa Theologica that, if the highest aim of a captain were merely to preserve their ship, then they would simply keep it in port forever. Of course, that is not the only goal of a captain has. The safety of the vessel and the crew is essential, of course, but captains brave the high seas because there are good reasons to take such risks. Most obviously, it might be how they make their living. But historically, captains have also taken to the seas as pioneering explorers, researchers, or even just thrill-seekers.

This was equally true when humans first decided to take to the air in balloons, blimps, airplanes, and rockets. A strict application of the precautionary principle would have instead told us we should keep our feet on the ground. Better to be safe than sorry! Thankfully, many brave souls ignored that advice and took the heavens in the spirit of exploration and adventure. As Wilbur Wright once famously said, “If you are looking for perfect safety, you would do well to sit on a fence and watch the birds.” Needless to say, humans would have never mastered the skies if the Wright brothers (and many others) had not gotten off the fence and taken the risks they did.

Opportunity Costs Matter

Here we get to the true danger of strict versions of the precautionary principle: It essentially becomes a crime to get off the fence and do anything risky at all. This sets up the potential for stasis and stagnation as societal learning is severely curtailed. Progress becomes harder because there can be no reward without some risk. — both individually or societally. “Caution makes sense except when it doesn’t,” Bauer notes. She continues on to note:

Used too liberally, the precautionary principle can keep us stuck in a state of extreme risk-aversion, leading to cumbersome policies that weigh down our lives. To get to the good parts of life, we need to accept some risk.

As I argued in a book on these issues, the root problem with precautionary principle thinking is that “living in constant fear of worst-case scenarios—and premising public policy on them—means that best-case scenarios will never come about.” If societal attitudes and public policy will not tolerate the idea of any error resulting from experimentation with new and better ways of doing things, then we will obviously not get many new and better things! Scientist Martin Rees refers to this truism about the precautionary principle as “the hidden cost of saying no.”

The opportunity cost of inaction or stasis can be hard to quantify but imagine if we organized our entire society around a rigid application of the precautionary principle. Bauer notes that this is basically what we did during COVID. And the results are in. “It’s far past time we ask ourselves when abundance really means excess, when our precautionary measures against Covid have gone too far, when we have ignored the costs and lost all sense of proportionality.” Unfortunately, the precautionary mindset–which is always rooted in fear of the unknown–took control. As Bauer notes:

It should have been socially acceptable to debate the merits of these tradeoffs, with nuance and without censure. But that is not what happened. Early in the pandemic, an unspoken rule — thou shalt not question the costs — sprang up and stifled discourse.

“And here’s the worst of it: the costs of excess caution can persist long after the initial danger has passed,” she notes. “It’s no different with Covid: our knee-jerk caution may have downstream effects that persist after the virus has ceased to be a threat.” She cites many compelling examples of the negative effects associated with extreme precautionary thinking during COVID, noting how, “[t]he impact of travel and trade restrictions on food security and childhood vaccination in developing countries will likely reverberate for decades.” Moreover:

The Covid-19 pandemic has laid bare the risks of extreme protection: lost businesses, lost livelihoods, lost graduations, lost loves, lost goodbyes; the loss of personal agency over life’s most intimate and meaningful moments; the loss, quite possibly, of our cherished principles of liberal democracy. A recent report by International IDEA, a democracy advocacy organization, concluded that many countries had become more authoritarian as they took steps to contain the pandemic.

This list of lockdown trade-offs goes on and the aggregate costs will be staggering once economists and others get around to better estimating them. As noted, gauging those costs will be challenging because of the many variables and values that come into play. But it remains vital that society takes risk analysis and trade-offs more seriously so that we don’t make these mistakes again and again.

Proportionality is the Key

Toward that end, Bauer makes “a plea for proportionality.” She wants society to strike a more reasonable balance when it comes to policy measures that might block actions and research that could help us better understand how to deal with risk uncertainties. Accordingly, “we must understand when to apply the precautionary principle and when to move on from it.”

“The precautionary principle doesn’t come with such checks and balances. On the contrary, it tends to perpetuate itself and acquire a life of its own,” she notes. In other words, once set in place initially for a given issue or sector, precautionary principle thinking tends to grow like bad weeds until it has taken over everything in sight. (To see the consequences of that in fields like aviation, space, nanotech, and others, please check out J. Storrs Hall’s amazing new book, Where Is My Flying Car?)

Of course, proportionality cuts both ways, and as I noted in my last two books, there are some instances in which at least a light version of the precautionary principle should be preemptively applied, but they are limited to scenarios where the threat in question is tangible, immediate, irreversible, and catastrophic in nature. In such cases, I argue, society might be better suited thinking about when an “anti-catastrophe principle” is needed, which narrows the scope of the precautionary principle and focuses it more appropriately on the most unambiguously worst-case scenarios that meet those criteria. Generally speaking, however, this test is not satisfied in the vast majority of cases. “Innovation Allowed” should be our default principle. 


The single most important thing that we must always remember when debating precautionary principle-based policies is that, just because someone has good intentions and claims safety as their goal, that does not automatically make the world a safer place. To repeat: Excessive safety-related measure can result in less safety overall. Or again, as Bauer says, “extreme caution comes at a cost.”

No one ever summarized this truism more clearly than the great political scientist Aaron Wildavsky, who devoted much of his life’s work to proving how efforts to create a risk-free society would instead lead to an extremely unsafe society. In his 1988 book, Searching for Safety, Wildavsky warned of the dangers of “trial without error” reasoning, and contrasted it with the trial-and-error method of evaluating risk and seeking wise solutions to it. He argued that wisdom is born of experience and that we can learn how to be wealthier and healthier as individuals and a society only by first being willing to embrace uncertainty and even occasional failure. Here was the crucial takeaway:

The direct implication of trial without error is obvious: If you can do nothing without knowing first how it will turn out, you cannot do anything at all. An indirect implication of trial without error is that if trying new things is made more costly, there will be fewer departures from past practice; this very lack of change may itself be dangerous in forgoing chances to reduce existing hazards. . . . Existing hazards will continue to cause harm if we fail to reduce them by taking advantage of the opportunity to benefit from repeated trials.

Trial and error is the basis of all societal learning, and without it, humanity will be less safe and less prosperous over the long run. Gabrielle Bauer’s new essay captures that insight better than anything I’ve read since Wildavsky was writing about the dangers of the precautionary principle. I beg you to jump over to New Atlantis and read her entire article. It’s absolutely essential.


Additional reading from Adam Thierer on the precautionary principle

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