  The deep X-ray, optical, and far-infrared fields that constitute GOODS are
sensitive to obscured AGN (N_H>10^{22} cm^{-2}) at the quasar epoch (z~2-3), as
well as to unobscured AGN as distant as z~7. Luminous X-ray emission is a sign
of accretion onto a supermassive black hole and thus reveals all but the most
heavily obscured AGN. We combine X-ray luminosity functions with appropriate
spectral energy distributions for AGN to model the X-ray, optical and
far-infrared flux distributions of the X-ray sources in the GOODS fields. A
simple model based on the unified paradigm for AGN, with ~3 times as many
obscured AGN as unobscured, successfully reproduces the z-band flux
distributions measured in the deep HST ACS observations on the GOODS North and
South fields. This model is also consistent with the observed spectroscopic and
photometric redshift distributions once selection effects are considered. The
previously reported discrepancy between observed spectroscopic redshift
distributions and the predictions of population synthesis models for the X-ray
background can be explained by bias against the most heavily obscured AGN
generated both by X-ray observations and the identification of sources via
optical spectroscopy. We predict the AGN number counts for Spitzer MIPS 24 um
and IRAC 3.6-8 um observations in the GOODS fields, which will verify whether
most AGN in the early Universe are obscured in the optical. Such AGN should be
very bright far-infrared sources and include some obscured AGN missed even by
X-ray observations.
