Public Safety Legislation and the Risk Compensation Hypothesis: The Example of Motorcycle Helmet Legislation

The ‘experiment’ in the United States of America in which twenty-eight states in the latter half of the 1970s repealed their laws which made the wearing of motorcycle helmets compulsory is widely believed to have proved conclusively that helmet legislation is a highly effective public health measure. The principal statistical foundations of this belief are found in a report to Congress by the National Highway Traffic Safety Administration and in a study by Watson et al. These foundations are examined and found to be open to criticism.

The evidence surveyed here suggests that the effect, if any, of helmet legislation on motorcycling fatalities is perverse. The ‘risk compensation theory’ is proffered as a possible explanation of the available evidence.