  The latest cosmological constraints on the sum of neutrino masses, in
combination with the latest laboratory measurements on oscillations, provide
``decisive" Bayesian evidence for the normal neutrino mass hierarchy. We show
that this result holds across very different prior alternatives by exploring
two extremes on the range of prior choices. In fact, while the specific
numerical value for the Evidence depends on the choice of prior, the Bayesian
odds remain greater than 140:1 across very different prior choices. For
Majorana neutrinos this has important implications for the upper limit of the
neutrino-less double beta decay half life and thus for the technology and
resources needed for future double beta decay experiments.
