In addition, there is currently a publication inflation affecting many aspects of science, and related to the infamous journal impact factor. For example: in t

In addition, there is currently a publication inflation affecting many aspects of science, and related to the infamous journal impact factor. For example: in the past, only Science, Nature and Cell indulged in generating "previews", that is, little summary papers published within the same journal number as the papers it summarizes and cites. The only reason: to increase impact factor. Why little journals didn't do it amounted to economic reasons: no time, no resources (all papers were dead-tree paper), and naivete. But nowadays many little journals have caught on, and publish editorial previews which, to hide a bit their real motivation, are often written not by editors but by invited authors from the same field. Then there is the need for evaluation: how can a scientist evaluate another scientist from a different field? It's hard, and worse, it's very time consuming if it has to be done right. The truth is that it's easier to simply look at the number of publications and particularly, at the impact factor of the journals in which they were published. Which is no replacement, but it's used as if it is. In all, what in the 1980's would have been one nice big, consistent paper, nowadays is published in multiple, small papers that cite each other in a chain. Just so your resume looks bigger that your competitors for those precious tenure track or group leader positions in science. This phenomenum is being institutionalized in the form of an increasing required amount of papers (no one ever mentions quality!) to be able to graduate and get your PhD!