We identify nearby disk galaxies with optical structural parameters similar
to those of intermediate-redshift compact blue galaxies. By comparing HI and
optical emission-line widths, we show that the optical widths substantially
underestimate the true kinematic widths of the local galaxies. By analogy,
optical emission-line widths may underrepresent the masses of intermediate-z
compact objects. For the nearby galaxies, the compact blue morphology is the
result of tidally-triggered central star formation: we argue that interactions
and minor mergers may cause apparently compact morphology at higher redshift.Comment: 5 pages, uses emulateapj5 and psfig. To appear in ApJ