Various scaling relations between monochromatic 1.4 GHz luminosity (L_{1.4 GHz}) and kinetic luminosity (L_kin) from the literature, as indicated in the top left of the panel and described in detail in the text (see Eq. (A.1)). Also shown, to guide the eye, are the data used by Bîrzan et al. (2004) and O’Sullivan et al. (2011) (L_{1.4 GHz}≈ 10²⁰ − 10²⁸ W Hz^-1; filled symbols). The analytically derived Willott et al. (1999) relation shown is that for f_W = 15 (see text for details) in agreement with the relations based on a combination of X-ray cluster/group and radio data (symbols). For f_W = 4, it would agree with the Daly et al. (2012) relation inferred for powerful radio galaxies (L_{1.4 GHz}> 10²⁷ W Hz^-1).