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Risk homeostasis: a win-win situation?
  1. I B Pless, Editor

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    The Opinion/Dissent columns in this issue deal with one of the most contentious ideas in the safety field. The notion of risk homeostasis crops up constantly—in letters to the editor, in scientific articles, and in political debates. Although Wilde has been careful to present his controversial ideas as “theory”, others treat them as proved. It seemed wise for this issue to be aired fully and this prompted my invitation to Professor Wilde to explain risk homeostasis to our readers.

    It did not seem reasonable, however, to do so without providing an opportunity for rebuttal by those who are convinced that there is little or no foundation for Wilde's beliefs. Thus, quite coincidentally, I invited Brian O'Neill and Allan Williams of the IIHS mentioned above, to prepare a Dissent.

    In brief, Wilde argues that measures taken to diminish risk are offset by behaviours that increase risk. Thus, a balance is maintained such that we should not expect to see any reduction in injuries accruing to new safety measures. Wilde believes that the only way to succeed in light of his theory is to somehow persuade the public to lower their acceptable level of risk taking. This is akin to setting the thermostat in your home to a lower temperature.

    Wilde's critics point to flaws in his reasoning and misinterpretations of the data used to support this theory. In fact, some believe the data actually point to the opposite conclusions: that safety measures have had, for the most part, the intended effects. They note that restrained drivers do not drive faster. Certainly in the case of restrained children, there is nothing to suggest that after taking such measures to protect a child, a parent is then more inclined to carelessness in other aspects of car safety. If anything, we suspect that the reverse is true.

    But instincts are often misleading and what is needed is solid scientific evidence and dispassionate judges of that evidence. Wilde and Williams and O'Neill marshall some of the data we need to draw our own conclusions. This debate will not soon or easily be resolved. And it may be that in some strange way, both sides will be shown to be right: that for safety advocates, the debate can be turned into a win-win situation.

    What may be needed is that we heed Wilde's bottom line: that the level of acceptable risk must be lowered. Although it is not clear how this can be accomplished, there may be little reason for rejecting the notion out of hand. The only dissenters may be those who suggest that children can only learn to avoid harm by being injured. This idea is even more contentious (and, in my view, more foolish). But it, too, may deserve further scrutiny. If we knew how to persuade parents or children to lower their risk taking thermostats, surely we should do so.

    At the same time, however, it would be folly on the strength of Wilde's arguments to abandon attempts to introduce new safety measures or not to implement those we have shown to be effective. On the contrary, whether we accept the Dissenting view or not, the experience of every safety group and most researchers tells us that technology, legislation, regulations, and education have all worked successfully together in the past to enhance child safety. They should continue to do so possibly with a little from our friends in psychology. Are crackdowns what they are cracked up to be?

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