Redshift evolution of the number density (top panel), and luminosity density (bottom panel) for our radio AGN (for models as indicated in the panels; see text for details). The number density was integrated with a lower boundary of L_{1.4 GHz}= 10²² W Hz^-1. Decreasing the boundary would systematically shift the number densities to higher values (for example, by a factor of 3–5 if L_{1.4 GHz}= 10²¹ W Hz^-1 were used). The luminosity density integral has a much weaker dependence on the integration limits (if it is broad enough) as the bulk of the integral is constrained close to (L^∗,Φ^∗).