Will the increase in publication volumes “dilute” prestigious journals’ impact factors? A trend analysis of the FT50 journals

In the wake of the unprecedented global scientific output boom, are top-tier journals such as the FT50 journals following suit? If these prestigious journals consistently increase their publication volumes, will their impact factors be affected? Drawing on the Mann–Kendall trend test method, this study analysed time series trends of the FT50 journals’ annual publication volumes and impact factor ratios (IFR) over a 15 year period. The results indicate that half of the FT50 journals have consistently increased their publication volumes over the years. Although to increase publication volumes is riskier than to stay put, it has a significantly higher probability of increasing the IFR, and therefore keeping pace with other top journals. However, the expanding of publication volumes must be carried out cautiously, as the study also finds that growing too fast may lead to opposite effects.