  An analysis of the kinematics of 412 stars at 1-4 kpc from the Galactic
mid-plane by Moni Bidin et al. (2012) has claimed to derive a local density of
dark matter that is an order of magnitude below standard expectations. We show
that this result is incorrect and that it arises from the assumption that the
mean azimuthal velocity of the stellar tracers is independent of Galactocentric
radius at all heights. We substitute the assumption, supported by data, that
the circular speed is independent of radius in the mid-plane. We demonstrate
that the assumption of constant mean azimuthal velocity is implausible by
showing that it requires the circular velocity to drop more steeply than
allowed by any plausible mass model, with or without dark matter, at large
heights above the mid-plane. Using the approximation that the circular velocity
curve is flat in the mid-plane, we find that the data imply a local dark-matter
density of 0.008 +/- 0.003 Msun/pc^3 = 0.3 +/- 0.1 GeV/cm3, fully consistent
with standard estimates of this quantity. This is the most robust direct
measurement of the local dark-matter density to date.
