Footnotes

• Contributors The content of the article reflects SG’s long-standing ideas about the topic. He drafted the original column, revised following feedback from SF and approved the final version. He is accountable for all of the content. SF suggested the topic to SG and provided critical revisions to the original draft. She also gave final approval for the submitted version and is accountable for all of the content.

• Funding This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.