The large-scale bias function, F, measured for a toy model with known solution (top) and for unbiased tracers (bottom). Coloured shaded regions show the measurement (and jackknife error) at different damping scales and the grey regions show different realisations at k_d = 0.1 h Mpc⁻¹. At larger damping scales the measurement gets generally biased at smaller values of δ. The jackknife errors underestimate the uncertainty, since the measurement is sensitive to rare outliers, but we can estimate the validity range of the measurements as where unbiased tracers have F ∼ 1.