Posterior predictive distribution in the median value of the central stellar velocity dispersion σ_e, from mock realisations of sets of 23 SuGOHI lenses, generated from the posterior probability distribution inferred for the “Arctan” (black solid) and “Gaussian” (red dotted) models. The vertical line marks the median value of the stellar velocity dispersion of the lenses in our sample, as measured by BOSS. The percentages left and right of the vertical line indicate the fraction of mock realisations with a median σ_e smaller or larger than the observed value, for the two models.