Top panel: redshift distributions of the galaxy samples analysed. Shown are the histograms for the SDSS LRG samples in black (faint, M_r >  −22.3), blue (medium,  −22.6 < M_r <  − 22.3), and purple (bright, M_r <  −22.6), for the full MegaZ-LRG sample in red, and for the SDSS Main samples in green (L4) and orange (L3). Note that both SDSS LRG and MegaZ-LRG samples are split into two redshift bins each, the SDSS LRG samples at z = 0.27 and the MegaZ-LRG sample at z = 0.529. Bottom panel: distribution of rest-frame absolute magnitudes M_r. The colour coding of the histograms is the same as in the top panel. In the case of the SDSS LRG and MegaZ-LRG samples solid lines correspond to the low redshift bin, dotted lines to the high redshift bin, respectively. Note that the MegaZ-LRG histograms rely on photometric redshift estimates, and that they have been downscaled by a factor of 20 to facilitate the comparison with the other samples.