Top: M_BH with effect of orientation via Eq. (10) vs. the “true” M_BH, for a synthetic sample of 10 000 sources. Second from top: M_BH C IVλ1549 vs. M_BH Hβ estimated for an Eddington ratio distribution as described in the text and no correction. Third from top: FWHM M_BH C IVλ1549 corrected because of outflow broadening using a correction factor ξ. The blue dots identify the M_BH Hβ estimates that are under 0.33 dex the true M_BH; the red ones are for overestimates by more than 0.33 dex. The gray dots represent mass estimates within −0.33 and +0.33 dex from the true value. Fourth from top: as above but with color-coding referring to C IVλ1549 M_BH. Bottom: synthetic sample with n ≲ 80 sources, as in the FOS+HE sample. See text for more details. In all panels, the dot-dashed line is the equality line; the filled line traces an unweighted least-squares fit.