Bias on lens mass properties as a function of the minimum Einstein radius. First panel: median log α_sps. Dotted lines indicate values of α_sps corresponding to a Chabrier and a Salpeter IMF (α_sps = 1 corresponds to a Kroupa IMF). Second panel: median M_h at log = 11.4. Third panel: median M_DM, 5 at log = 11.4 and log R_e = 1.2. Fourth panel: median γ_DM at log = 11.4 and log R_e = 1.2. In each panel, the dashed line indicates the value of the parent population. Error bars indicate the standard deviation of the mean of the lens sample.