Finally we consider the evolution of the black hole mass density in Figure 7. The grey band represents the observed z = 0 density from Shankar et al. (2009) and BS09 slightly overestimates this value. The model of PNK11 produces a density that is a factor of three smaller than BS09 at z = 0 and also outside the observed value. Overall, PNK11 has a smooth evolution of the density with redshift. BS09 has a less smooth distribution and grows in three stages.  Tremaine et al. (2002). This is different to the scatter on the **data** which is larger. BS09 is well fit by the observations, but PNK11 tends to produce larger velocity dispersions for high mass black holes. BS09 PNK11 Figure 5. The M BH − M * relation for BS09 (left) and PNK11 (right). The red line and shading represents the observed best fit and the uncertainty on this fit from Marleau et al. (2012). This is different to the scatter on the **data** which is larger. BS09 is well fit by the observations, but tends to produce higher stellar mass galaxies for low mass black holes. PNK11 tends to produce larger stellar mass galaxies for high mass black holes. has a lower black hole accretion rate to BS09, which weakens the feedback leading to high mass galaxies becoming too massive.