  We gain insight into the effects of gravitational lensing on the estimated
distribution of merging binaries observed through gravitational waves. We
quantify the efficiency of magnification for gravitational wave events in the
geometric optics limit, and we compare it to the electromagnetic case by making
minimal assumptions about the distribution of intrinsic properties for the
source population. We show that lensing effects leave a recognizable signature
on the observed rates, and that they can be prominent only in the presence of
an extremely steep mass function (or redshift evolution) and mainly at low
inferred redshifts. We conclude that gravitational magnification does not
represent a significant systematic for gravitational wave merger studies in the
LIGO-Virgo era.
