  Recent determination of the outer rotation curve of the Galaxy suggests that
the total Galactic mass is likely to concentrate into a region of radius
$\sim2R_0$. If this finding is correct, the previously estimated optical depth
of microlensing events towards the Large Magellanic Cloud (LMC) should be
correspondingly reduced.
  It appears that a truncated Galactic halo model instead of the standard
isothermal one extending to LMC accounts naturally for the reported
microlensing rate by the MACHO collaboration. Such an explanation is indeed
obvious yet has been overlooked in the past.
