  We propose a general framework that unifies the point of view of counting
statistics of transmitted (fermionic) charges as it is commonly used in the
quantum transport community to the point of view of counting statics of phonons
(bosons) as it is known from the field of quantum optics. As a particular
example, we study on the same footing the counting statistics of electrons
transfered through a molecular junction and the corresponding population
dynamics of the associated molecular vibrational mode. In the tunnel limit,
non-perturbative results in the electron-phonon interaction are derived that
unify complementary approaches based on rate equations or on the use of
non-equilibrium Green functions.
