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We employ a flexible Bayesian technique to estimate the black hole mass andEddington ratio functions for Type 1 (i.e., broad line) quasars from auniformly-selected data set of ~58,000 quasars from the SDSS DR7. We find thatthe SDSS becomes significantly incomplete at M_{BH} < 3 x 10^8 M_{Sun} or L /L_{Edd} < 0.07, and that the number densities of Type 1 quasars continue toincrease down to these limits. Both the mass and Eddington ratio functions showevidence of downsizing, with the most massive and highest Eddington ratio blackholes experiencing Type 1 quasar phases first, although the Eddington rationumber densities are flat at z < 2. We estimate the maximum Eddington ratio ofType 1 quasars in the observable Universe to be L / L_{Edd} ~ 3. Consistentwith our results in Paper I, we do not find statistical evidence for aso-called "sub-Eddington boundary" in the mass-luminosity plane of broad linequasars, and demonstrate that such an apparent boundary in the observeddistribution can be caused by selection effect and errors in virial BH massestimates. Based on the typical Eddington ratio in a given mass bin, weestimate typical growth times for the black holes in Type 1 quasars and findthat they are typically comparable to or longer than the age of the universe,implying an earlier phase of accelerated (i.e., with higher Eddington ratios)and possibly obscured growth. The large masses probed by our sample imply thatmost of our black holes reside in what are locally early type galaxies, and weinterpret our results within the context of models of self-regulated black holegrowth.

The Demographics of Broad Line Quasars in the Mass-Luminosity Plane II. Black Hole Mass and Eddington Ratio Functions