Radio loudness R₁₅₀ for the MWQSO sample, as a function of the q_IRC-value, which parametrises the IR-radio correlation. The central panel shows the posterior median values for red QSOs and the control sample. The upper panel shows the combined distribution of the q_IRC posteriors (100 realizations per source) for the two samples, obtained from the Bayesian SED fitting. The grey shaded area represents the value of q_IRC found by Calistro Rivera et al. (2017) for star forming galaxies at 150 MHz q_{IRC − 150 MHz} = 1.54 with a scatter of 0.5. The right panel shows the combined distribution of the R₁₅₀ values for the two samples.