Abstract :
I studied the distribution of changes in journal impact factors (JIF) between 1998 and 2007 according to an empirical beta law with two exponents. Changes in JIFs (CJIF) were calculated as the quotient obtained by dividing the JIF for a given year by the JIF for the preceding year. The CJIFs showed good fit to a beta function with two exponents. In addition, I studied the distribution of the changes in segments of the CJIF rank order. The distributions, which were similar from year to year, could be fitted to a Lorentzian function. The methods used here can be useful to understand the changes in JIFs using relatively simple functions.
