Adding insult to injury, in practice this rule assumes that new prohibitions or regulations will result in no harm to human health or the environment. Unfortunately, well-intended interventions into complex systems invariably have unintended consequences. Only by closely examining possible ramifications can we determine whether or not the intervention is likely to make us better off. By single-mindedly enforcing the tyranny of safety, this principle can only distract decision makers from such an examination.
Our choices of modes of transport provide a simple example of the paradox of the precautionary principle. What image comes to mind when we hear the words “airplane crash”? A terrifying plunge, an enormous smash, hundreds of dead bodies, billows of black smoke. On hearing news of a spectacular plane crash, some travelers choose to go by car instead. (A smaller number of people won’t take a plane at any time, though they rarely claim this to be a calmly rational choice.) The same effect has been observed in the case of train accidents. Plane and train crashes are dramatic events that impress themselves on our minds, encouraging us to believe that those modes of travel are intolerably risky. The facts are otherwise—as most of us know, if only vaguely.
Consider that in 2000, the world’s commercial jet airlines suffered only 20 fatal accidents, yet they carried 1.09 billion people on 18 million flights. Even more remarkable, if you add up all the people who died in commercial airplane accidents in America over the last 60 years, the number you will arrive at is smaller than the number of people killed in U.S. car accidents in any three-month period. These totals are telling, but the most relevant figures compare fatalities per unit of distance traveled. By that measure, in the United States you will be 22 times safer traveling by commercial airline than by car. (This conclusion is from a 1993-95 study by the U.S. National Safety Council.)
Air travel has become much safer since 1950, bringing down the number of fatal accidents per million aircraft miles flown to 0.0005. To put your risk of death into proportion, consider that in 1997 commercial airlines made 8,157,000 departures, carried 598,895,000 passengers, and endured only 3 fatal accidents. While switching from road to air reduces your risk 22 times, if you were to switch from train to air, you would reduce your risk 12-fold.
You’re considerably more likely to die while engaging in recreational boating or biking than while traveling by air. Given that you need to travel, by taking a precautionary approach that leads you to avoid the possibility of a spectacular air crash, you would be exposing yourself to a greater risk of injury or death. Be cautious with precaution!
In comparing the fatality rates of air travel and road travel, we have been comparing like with like. The paradox of the precautionary principle becomes even more dangerous when a preoccupation with one value, such as safety, distracts us from other values. We may be able to improve an outcome according to one measure, but it will often come at the cost of worsening an outcome according to a different measure. In that case we will face choices that the precautionary principle is poorly equipped to handle. To see this, consider the Kyoto protocol.
The Kyoto protocol is an international precautionary commitment to reduce the emission of gases suspected of causing global warming. Supporters of Kyoto typically favor forcing down emissions of these gases by raising fuel economy standards for cars and trucks. The effects of enforcing similar fuel economy standards in the United States has pushed automakers to come out with smaller, lighter, more vulnerable cars. According to a study by the Harvard School of Public Health, this results in an additional 2,000-4,000 highway deaths per year. In this case, we are buying some climate remediation at the cost of many lives. We are improving outcomes according to one measure but worsening them according to another measure.
Regulation of economic activity—whether precautionary in origin or not—involves a more general and well-established tradeoff. Known as the “income effect”, this tradeoff is shaped by a correlation between wealth and health. Implementing and complying with regulations imposes costs. Political scientist Aaron Wildavsky observed that poorer nations tend to have higher mortality rates than richer ones. This correlation is no coincidence. Wealthier people can eat more varied and nutritious diets, buy better health care, and reduce sources of stress (such as excessively long working hours) and thereby reduce consequences such as heart attacks, hypertension, depression, and suicide.
In counting up the anticipated benefits of regulations, we should therefore also consider what they may cost us—or cost poorer people in countries affected by international regulations. Some regulations will amount to a lousy deal. Although precise numbers are hard to pin down, a conservative estimate from the research suggests that the income effects leads to one additional death for every $7.25 million of regulatory costs. Many regulations impose costs in the tens of billions of dollars annually. That implies thousands of additional deaths per year. Safety is not free. Regulatory overkill can be just that.
If only activists would appreciate this point as they move from opposing chlorine to opposing “endocrine disruptors” and phthalates (used to soften plastics). The story of the antichlorine campaign does not offer much hope. The price of precaution can be exorbitant, especially for developing countries. Toward the end of the 1980s, environmental activists had focused their attention on purging society of chlorinated compounds. As part of this campaign, activists spread disinformation in all directions. They worked especially hard to persuade water authorities in numerous countries that allowing chlorination of drinking water amounted to giving people cancer. In Peru, they succeeded. The consequences were dire.
Finding themselves in a budget crisis, Peruvian government officials saw in the cancer-risk claims a handy excuse to stop chlorinating the drinking water in many part of the country. They could cover their backs by pointing to official reports from the US Environmental Protection Agency that had alleged that drinking chlorinated water was linked to elevated cancer risks. (The EPA later admitted that this connection was not “scientifically supportable.”) Soon afterwards, cholera—a disease that had been wiped out in Peru—returned in the epidemic of 1991-96. 800,000 suffered and 6,000 died in Peru. Then it spread to Columbia, Brazil, Chile, and Guatemala. Around 1.3 million people were afflicted, and 11,000 or more were killed by the disease.
The drinking water system had been deteriorating before this, so we cannot place the entire blame on the single decision to stop chlorinating. But chlorinating the water would probably have prevented the epidemic from getting started. Absence of the treatment certainly made the situation far worse. The high price paid for that precautionary measure is not unusual or surprising in poorer countries. The elimination of DDT further illustrates the point.
DDT ended the terrible scourge of malaria in some third-world countries by the late 20th century by ending malaria-carrying mosquitoes. But environmentalists targeted the pesticide, claiming that it might harm some birds and might possibly cause cancer. Malaria control efforts around the world quickly fell apart. This devastating affliction of nature is rapidly gaining strength in earth’s tropical regions. Malaria epidemics in 2000 alone killed over a million people and sickened 300 million. Once again, those least able to bear it were the ones to pay the high price for precautionary tunnel vision.
Have aggressive environmental activists learned from these experiences and changed course? Hardly. “Green at any price” seems to be their motto as they mutter speculations of doom while trying to strangle the technology of gene-spliced (or “genetically modified” or GM) crops. In this case, there may be hope. Late in 2004, both China and Britain looked set to approve gene-spliced crops, despite well-organized and funded opponents—opponents who don’t hesitate to destroy crops being grown for research. And in 2005, the FDA began loosening its restrictions on bioengineered rice.
If these countries open the way for this vital part of agricultural biotechnology, it will mean a reversal of years of public policy that has restricted and raised costs of research and development. The result should be to spur innovation and to renew food productivity growth in the developing countries., ushering in a second Green Revolution.
These are just a few of the many cases illustrating the dangers of the precautionary principle. Environmental and technological activism that wields the precautionary principle, whether explicitly or implicitly, raises clear threats of harm to human health and well-being. If we apply the principle to itself, we arrive at the corollary to the Paradox of the Precautionary Principle:
According to the principle, since the principle itself is dangerous, we should take precautionary measures to prevent the use of the precautionary principle.
The severity of the precautionary principle’s threat certainly does not imply that we should take no actions to safeguard human health or the environment. Nor does it imply that we must achieve full scientific certainty (or its nearest real-world equivalent) before taking action. It does imply that we should keep our attention focused on established and highly probable risks, rather than on hypothetical and inflated risks. It also implies an obligation to assess the likely costs of enforcing precautionary restrictions on human activities. Clearly, we need a better way to assess potential threats to humans and the environment—and the consequences of our responses. In order to develop a suitable alternative, we first need to appreciate the full extent of flaws in the precautionary approach.
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