  The properties of relativistic radio jets are thought to be closely connected
with the properties of accretion disks in active galactic nuclei. We explore
this issue using a sample of 35 blazars with very-long baseline observations,
for which we can estimate the kinetic powers of their relativistic jets, the
bolometric luminosity of their accretion disks, and the masses of their black
holes. Contrary to previous claims, we find that the jet kinetic power is
significantly correlated with the disk luminosity. This supports the notion
that the disk is somehow coupled to the jet, even on parsec scales. Moreover,
we show that the correlation improves by including the black hole mass as a
second parameter. The dominance of the jet, parameterized as the ratio of the
jet kinetic power to the disk luminosity, is largely controlled by and is
inversely correlated with the Eddington ratio of the accretion disk. This
empirical relation should serve as a useful guide for theoretical models for
jet formation.
