  We reconsider the commonly held assumption that warm debris disks are tracers
of terrestrial planet formation. The high occurrence rate inferred for
Earth-mass planets around mature solar-type stars based on exoplanet surveys
(roughly 20%) stands in stark contrast to the low incidence rate (less than
2-3%) of warm dusty debris around solar-type stars during the expected epoch of
terrestrial planet assembly (roughly 10 Myr). If Earth-mass planets at AU
distances are a common outcome of the planet formation process, this
discrepancy suggests that rocky planet formation occurs more quickly and/or is
much neater than traditionally believed, leaving behind little in the way of a
dust signature. Alternatively, the incidence rate of terrestrial planets has
been overestimated or some previously unrecognized physical mechanism removes
warm dust efficiently from the terrestrial planet region. A promising removal
mechanism is gas drag in a residual gaseous disk with a surface density of
roughly or somewhat more than 0.001% of the minimum mass solar nebula.
