Effect of redshift-space distortions on the measurement and modelling of the clustering ratio. The values estimated in real and redshift space from the L_h halo catalogues (main panel) are compared with the theoretical predictions; these have been named and η_g,R respectively to indicate whether or not redshift-space distortions are included in the modelling. Each point represents the average over 31 mock catalogues (see text), while error bars give the corresponding standard deviation of the mean. The statistic is shown as a function of the filtering radius R and correlates the field on scales r = 3R. To obtain from Eq. (8) (solid line), we adopted a pairwise velocity dispersion σ₁₂ = 200   km   s^-1 (Bianchi et al. 2012; Marulli et al. 2012). The model accounts for both cases for non-linear evolution of the power spectrum by including the prescription of (Smith et al. 2003) into Eq. (2). The lower panel shows instead the relative difference between the LHS and left- and right-hand sides of Eq. (8) as a function of the same R. The shaded corridor indicates a ± 5% deviation.