Average galaxy bias as a function of void radius, R_void (left), and maximum overdensity in the surrounding region, Δ_max (right). The uncertainties correspond to the errors on the means. Note that, as shown in Fig. 2, voids with high values of Δ_max, which also tend to have high bias, are very scarce. At fixed R_void, the population is dominated by lower-Δ_max (lower-⟨b⟩ voids), which explains why the average bias only reaches ∼0.5 in the left panel of this figure.