Philip Ball’s column in email@example.com this week is about Richard Doll, and whether he should have stated in his publications that he received consultancy fees. The Nature journals’ policy on competing interests is summarized here. As ever, we welcome comments from scientists about the practice of declaring such interests, whether financial, ethical or personal, in published papers. How relevant are any or all of these conflicts to the strength of the scientific conclusions reported in a peer-reviewed paper? In particular, we welcome feedback about our own policy, via comments to this post.