of $B\sim -0.2$ (e.g., [@Iwasawa:1993ys], [@Page:2004kx], [@Bianchi:2007vn]). However, in all these works the values of $EW$ and $L_{\mathrm{X}}$ are obtained from individual observations of sources, and, as pointed out by @Jiang:2006vn and confirmed by @Shu:2010zr [@Shu:2012fk], flux variability might play an important role in the observed X-ray Baldwin effect. @Shu:2012fk recently found a clear anti-correlation between the equivalent width of the iron K$\alpha$ line and the luminosity for individual sources which had several [*Chandra*]{}/HEG observations. Using a sample of 32 radio-quiet AGN, they also found that the fit [*per source*]{} (i.e. averaging different observations of the same object) results in a significantly flatter slope ($B=-0.11\pm0.03$) than that done [*per observation*]{} (i.e. using all the available observations for every source of the sample; $B=-0.18\pm0.03$).

In order to compare the slope obtained by the simulations in the two different luminosity bands with real data, we fitted the data per source (33 AGN) of @Shu:2010zr (; obtained fixing $\sigma=1\rm\,eV$) with Eq.\[eq:fit\_XBE\] in the Seyfert and quasar regime. Consistently to what reported in @Shu:2010zr we did not use the 3 AGN for which only upper limits of $EW$ were obtained. Using the 28 AGN in the Seyfert regime we obtained that the best fit 