Impact metrics are creating their own problems in China (see Nature 502, 271; 2013).

By recognizing only the first and corresponding authors on a paper, for example, China's metrics are indirectly discouraging participation in research consortia. The practice is counterproductive in this era of collaborative science.

Furthermore, review articles do not count towards impact metrics in China, so they do not help to advance an author's academic career. Information overload means that multidisciplinary, scholarly and timely reviews are more in demand than ever. Review authors need comprehensive knowledge, expert insight and outstanding inductive and deductive abilities. We therefore believe that this apparent discrimination is unjustified.