Growth-adjusted impact factor

The denominator of an impact factor is a number of publications over a two-year interval. For a growing journal, the number of publications in the second year of this interval exceeds the number in the first. The more rapid the growth, the greater this difference. Publications in the first year are, of course, older than those of the second year. Journal growth skews the cite contributions to the impact factor metric numerator to the second year of the denominator interval. Since second year papers have not been around as long as those in the first year, this skewing depresses a journal impact factor. We explore this impact factor growth penalty and, thus, arrive at a simple way to growth-adjust an impact factor.