In 2012 we published an article in the Journal of Medical Ethics on the issue of mandatory cycle helmet legislation.1 Rather unexpectedly it generated a great deal of media interest. This was partially because some parts of the media mistakenly assumed that we had published an article about a new empirical study—rather than a normative piece about the iniquity of mandatory cycle helmet laws. But, it was also because the issue of cycle helmet legislation hits a real nerve in the cycling community. Following the media storm, Biegler and Johnson, followed by Trégouët, published formal responses to our article in this journal.2 ,3 Their responses were largely critical and in this paper we offer some replies to their key objections.

Normative analysis of public policy decisions (and public policy itself) should depend on sound empirical data as well as sensible use of this empirical data. Nonetheless, there are important differences between publications which set out to offer a systematic review of empirical data and publications which set out to offer an analysis of the ethical underpinnings of public policy. Our article took the latter form and, as such, we did not refer to all the various publications relating to the efficacy of cycle helmets and cycle helmet legislation.

Did this represent a case of publication bias? We think not. We were at pains to point out in our article that there was evidence in favour and against the efficacy of cycle helmets and cycle helmet legislation. We also made sure that we referred our readers to evidence on both sides of the argument. It is true that we omitted some peer reviewed publications which provide further reason to believe that helmets are very effective.4 But it is equally true that we omitted peer reviewed publications which …