Top panel: ratio between the number density of progenitor ETGs with stellar masses M_s > 10¹⁰   h^-1   M_⊙ at a given redshift and their expected z = 0 descendants as inferred from the clustering analysis of P10. The filled squares show the results from using the PML r-band LF estimates; open squares show the results for the B-band. Errorbars are only shown for the r-band result to improve clarity; errors for the B-band show similar amplitudes. The crosses correspond to the results from the photo-z based maximum likelihood method to calculate the LF in the r-band. The solid line shows the unit ratio and the grey shaded area shows the estimated cosmic variance in a 0.25 sq. degree light-cone survey divided in slices of Δz = 0.1. Obviously, the number density of high-redshift progenitors is higher than that of their z = 0 descendants; this is not the case for progenitors at z < 0.6 and their z = 0 descendants. Bottom panel: ratio between the luminosity density of progenitor ETGs and that of their z = 0 ETG descendants in the r- and B-bands (filled and open squares, respectively). Regardless of the progenitor redshift, the luminosity density ratios shown are consistent with the unit value.