Recognition of a researcher's impact should include a measure of his or her contribution as a peer reviewer in maintaining high scientific standards in research papers and grant applications (Nature 502, 287; 2013).

It should be feasible to create a reviewers' equivalent of the h-index — which measures the impact of research output in terms of its quantity and popularity. This might indicate, for example, the number and impact of journals and papers for which the reviewer has acted as a referee. Publishers releasing these figures would need to protect the blind or double-blind review process.

They could do this by using a central repository to assign these metrics to particular researchers through identifiers such as the Open Researcher and Contributor ID scheme (see Nature 485, 564; 2012).

As well as securing the reputation of reviewers, such a measure would benefit journals and publishers by encouraging more scientists to undertake refereeing.