  We derive accretion rate functions (ARFs) and kinetic luminosity functions
(KLF) for jet-launching supermassive black holes. The accretion rate as well as
the kinetic power of an active galaxy is estimated from the radio emission of
the jet. For compact low-power jets, we use the core radio emission while the
jet power of high-power radio-loud quasars is estimated using the extended
low-frequency emission to avoid beaming effects. We find that at low
luminosities the ARF derived from the radio emission is in agreement with the
measured bolometric luminosity function (BLF) of AGN, i.e., all low-luminosity
AGN launch strong jets. We present a simple model, inspired by the analogy
between X-ray binaries and AGN, that can reproduce both the measured ARF of
jet-emitting sources as well as the BLF. The model suggests that the break in
power law slope of the BLF is due to the inefficient accretion of strongly
sub-Eddington sources. As our accretion measure is based on the jet power it
also allows us to calculate the KLF and therefore the total kinetic power
injected by jets into the ambient medium. We compare this with the kinetic
power output from SNRs and XRBs, and determine its cosmological evolution.
