Ratio of w_p, early/w_p, late = b_early/b_late of the 14 control samples. The pairs are arranged in increasing masses (from top left to bottom left, continuing from top right to bottom right). In each panel, the red horizontal dashed line denotes the theoretically expected bias ratio r_b, th (in the absence of AB); the 3 numbers shown in blue are the masses of the early-analogous and late-analogous clusters (in unit of 10¹⁴ h⁻¹ M_⊙), and the probability for the pair to be drawn from the same parent population.