The editors respond:
The IJE data are certainly intriguing. We looked at the same data for Epidemiology and found a similar pattern—our impact factor and the number of submissions have generally risen together (Figure).
We are not quite sure what to make of this. This ecologic association might, as the IJE editors interpret it, be a causal effect of impact factor on submissions—an effect that was somehow missed by our previous comparison of two 6-month periods.1 We might equally well conjecture that epidemiologists are more likely to submit to journals that have recently published interesting papers. It is also possible that both our journals have benefitted from a rising tide of epidemiologic submissions, allowing both journals to be more selective and publish more citable papers. Then again, the two trends may simply reflect the natural growth of healthy journals.
1. Hernán MA, Wilcox AJ. We are number one but nobody cares—that’s good. Epidemiology. 2012; 23:509