Average time-lag measurement (left) and associated standard deviation (right) for various fractional flux contribution from the line f_BLR, and six different amplitude of microlensing of the continuum μ. For each pair (f_BLR, μ), 500 different quasar light curves have been generated, with a time lag τ = 100 days between the variation of the continuum and of the BLR. Note that due to the definition of f_BLR, the case f_BLR = 0.9 corresponds to an average contribution of the line of 0.9/1.9 = 0.47 to the total flux.