  We use a comprehensive database of black hole masses and nuclear luminosities
to investigate the relationship between radio emission and black hole mass. Our
sample covers a wide range of nuclear activity, from nearby inactive nuclei to
classical Seyfert 1 nuclei and luminous quasars. Contrary to some previous
studies, we find that the radio continuum power, either integrated for the
entire galaxy or isolated for the core, correlates poorly with black hole mass.
The degree of nuclear radio loudness, parameterized by the radio-to-optical
luminosity ratio R, also shows no clear dependence on black hole mass.
Radio-loud nuclei exist in galaxies with a wide range of black hole mass, from
\~ 10^6 to a few X 10^9 solar masses, and in a variety of hosts, from
disk-dominated spirals to giant ellipticals. We demonstrate that R is strongly
inversely correlated with L/L_E, the ratio of nuclear luminosity to the
Eddington luminosity, and hence with mass accretion rate. Most or all of the
weakly active nuclei in nearby galaxies are radio-loud, highly sub-Eddington
systems that are plausibly experiencing advection-dominated accretion.
