Cumulative fraction of ionizing photons contributed by AGN as a function of redshift ($f_{\mathrm{ion}}^{\mathrm{bh}}$) and the contribution from AGN in high-mass (M_* ≳ 10⁹ M_⊙) galaxies, as marked. We show results for two contrasting models of f_esc^bh: The first model is the fiducial model, where f_esc^bh ∝ M_*⁻¹, and the second model is the Merloni (Merloni et al. 2014) model, where f_esc^bh ∝ M_*. We also show the redshifts (z_reio) at which reionization is completed in both of these models.