  We study the transverse momentum ($Q_T$) distribution of an electro-weak
vector boson produced via the Drell-Yan mechanism, in the context of joint
resummation. This formalism allows for the simultaneous resummation of
logarithmic contributions that are enhanced at small $Q_T$ and at partonic
threshold. We extend joint resummation to next-to-next-to leading logarithmic
accuracy and we present resummed and matched results for three different
phenomenological setups. In particular, we study the production of a $Z$ boson
at the Tevatron and at the Large Hadron Collider (LHC), as well as the
production of a heavier $Z^\prime$ at the LHC. We compare our findings to
standard $Q_T$ resummation, as well as to fixed-order perturbation theory. We
find that joint resummation provides a moderate (but not flat) correction with
respect to $Q_T$ resummation and it leads to a reduction of the scale
dependence of the results. However, our study also shows some limitations of
this formalism. While the use of joint resummation for $Z$ production at the
Tevatron and $Z^\prime$ production at the LHC appears to be justified, our
implementation suffers from a stronger dependence on power corrections for
processes which are further away from threshold, such as $Z$ production at the
LHC, for which we cannot claim an improvement over standard $Q_T$ resummation.
