Joint posterior on the power-law slopes α₁ (NS mass range) and α₂ (BH mass range) for the full POWER LAW + DIP + BREAK model (green). The two-dimensional contours show 50% and 90% credible regions, while vertical dashed lines show one-dimensional 90% credible intervals. For comparison, we show the power-law slope inferred under the POWER-LAW fit to (blue) only the BBH and (orange) all GWTC-1 events. We recover α₁ < α₂ with 91% credibility; α₁ = α₂ in this model reduces to the POWER LAW + DIP model.