  We study the astrophysical impact of inaccurate and incomplete modeling of
the gravitational waveforms from compact binary coalescences (CBCs). We do so
by the matched filtering of complete inspiral-merger-ringdown (IMR) signals
with a bank of inspiral-phase templates modeled after the 3.5 post-Newtonian
TaylorT1 approximant. The rationale for the choice of the templates is
threefold: (1) The inspiral phase of the Phenomenological signals, which are an
example of complete IMR signals, is modeled on the same TaylorT1 approximant.
(2) In the low-mass limit, where the merger and ringdown phases last much
shorter than the inspiral phase, the errors should tend to vanishingly small
values and, thus, provide an important check on the numerical aspects of our
simulations. (3) Since the binary black hole (BBH) signals are not yet known
for mass-ratios above ten and since signals from CBCs involving neutron stars
are affected by uncertainties in the knowledge of their equation of state,
inspiral templates are still in use in searches for those signals. The results
from our numerical simulations are compared with analytical calculations of the
systematic errors using the Fisher matrix on the template parameter space. We
find that the loss in signal-to-noise ratio (SNR) can be as large as 60% even
for binary black holes with component masses m1 = 13M\odot and m2 = 20M\odot.
Also, the estimated total-mass for the same pair can be off by as much as 20%.
Both of these are worse for some higher-mass combinations. Even the estimation
of the symmetric mass-ratio {\eta} suffers a nearly 20% error for this example,
and can be worse than 50% for the mass ranges studied here. These errors
significantly dominate their statistical counterparts (at a nominal SNR of 10).
It may, however, be possible to mitigate the loss in SNR by allowing for
templates with unphysical values of {\eta}.
