Power-law slope γ_pl inferences obtained from HST imaging data for the 14 SLACS lenses within our selection cut from Shajib et al. (2020a,b). We derive a population distribution from these lenses to be applied on the subset of lenses without measured γ_pl from imaging data. The black dashed line indicates the population mean and the blue band the 1-sigma population width based on the 14 individual measurements (https://github.com/TDCOSMO/hierarchy_analysis_2020_public/blob/6c293af582c398a5c9de60a51cb0c44432a3c598/JointAnalysis/sample_selection.ipynb).