Marcus Munafò and Björn Brembs: The impact factor agenda
22.3.2013
The authors say "there are several converging lines of evidence which indicate that publications in high ranking journals are not only more likely to be fraudulent than articles in lower ranking journals, but also more likely to present discoveries which are less reliable [...]. Some of the sociological mechanisms behind these correlations have been documented, such as pressure to publish (preferably positive results in high ranking journals), leading to the potential for decreased ethical standards and increased publication bias in highly competitive fields. [...] In our view, Impact Factor generates an illusion of exclusivity and prestige based on an assumption that it will predict subsequent impact, which is not supported by empirical data."
http://blogs.bmj.com/bmj/2013/02/14/marcus-munafo-and-bjorn-brembs-the-impact-factor-agenda/