  We have carried out extensive first principles doping-dependent computations
of angle-resolved photoemission (ARPES) intensities in La$_{2-x}$Sr$_x$CuO$_4$
(LSCO) over a wide range of binding energies. Intercell hopping and the
associated 3-dimensionality, which is usually neglected in discussing cuprate
physics, is shown to play a key role in shaping the ARPES spectra. Despite the
obvious importance of strong coupling effects (e.g. the presence of a lower
Hubbard band coexisting with mid-gap states in the doped insulator), we show
that a number of salient features of the experimental ARPES spectra are
captured to a surprisingly large extent when effects of $k_z$-dispersion are
properly included in the analysis.
