Redshifts and absolute K-band magnitudes of red quasars and unobscured type 1 quasars. The 20 red quasars used in this study are denoted by red open circles, and the black dots indicate the red quasars listed in Glikman et al. (2007) and Urrutia et al. (2009) from which our sample is drawn. Four red quasars (0036−0113, 0817+4354, 1209−0107, and 1307+2338), which were not used in Kim et al. (2015b), are denoted by filled red circles. The comparison sample is made of 37 unobscured type 1 quasars from Kim et al. (2010; blue open triangles), and 623 SDSS unobscured type 1 quasars at 0.275 < z < 0.363 and 0.562 < z < 0.842 (gray dots).