  We compute the chemical evolution of the Galactic bulge in the context of an
inside-out model for the formation of the Milky Way. The model contains updated
stellar yields from massive stars. The main purpose of the paper is to compare
the predictions of this model with new observations of chemical abundance
ratios and metallicity distributions in order to put constraints on the
formation and evolution of the bulge. We computed the evolution of several
alpha-elements and Fe and performed several tests by varying different
parameters such as star formation efficiency, slope of the initial mass
function and infall timescale. We also tested the effect of adopting a primary
nitrogen contribution from massive stars. The [alpha/Fe] abundance ratios in
the Bulge are predicted to be supersolar for a very large range in [Fe/H], each
element having a different slope. These predictions are in very good agreement
with most recent accurate abundance determinations. We also find a good fit of
the most recent Bulge stellar metallicity distributions. We conclude that the
Bulge formed on a very short timescale (even though timescales much shorter
than about 0.1 Gyr are excluded) with a quite high star formation efficiency of
about 20 Gyr$^{-1}$ and with an initial mass function more skewed toward high
masses (i.e. x <= 0.95) than the solar neighbourhood and rest of the disk. The
results obtained here are more robust than previous ones since they are based
on very accurate abundance measurements.
