Comparison of pairwise signal of the “richness-selected” and the “reconstructed” sample of clusters. The richness-selected sample is potentially subject to selection bias, where the reconstructed sample is mass-selected, unbiased, and weighted to match the mass probability distribution of the richness-selected sample. Using the same galaxy selection as in Fig. 1, the biases of pairwise kSZ effect, pairwise velocity, and optical depth are 1.10 ± 0.19, 1.01 ± 0.11, and 1.00 ± 0.08.