Distribution of q‐values as a function of 60 μm luminosity. The crosses are for the IRAS 2 Jy sample of Yun et al. (2001). The squares with error bars are for the millimeter‐detected QSOs with steep radio spectral indices, and the triangles are millimeter‐ and radio‐detected sources with almost flat or rising spectral indices (Table 2). The solid line marks the average value of ﹩q=2.34﹩, while the dotted lines mark the radio‐excess (lower) and IR‐excess (upper) objects, as discussed in Yun et al. (2001).