Magnitude-redshift diagram of VIPERS blue galaxies. Top panel: scatter plot in the magnitude (M_B)-redshift plane. Dark dots represent galaxies included in the volume-limited sample while the light dots show the ones excluded due to the luminosity threshold. Points show the luminosity threshold estimated by imposing a constant comoving number density as a function of redshift. The continuous lines are the best-fit model (Eq. (4)) to the points while the dashed curve represents the 90% completeness level of the survey. Bottom panel: a zoom-in to highlight the agreement between data and model for the luminosity evolution.