  Best-fit values of recent global analyzes of neutrino data imply large solar
neutrino mixing, vanishing U_{e3} and a non-maximal atmospheric neutrino mixing
angle theta_{23}. We show that these values emerge naturally by the hypothesis
of "scaling" in the Majorana neutrino mass matrix, which states that the ratios
of its elements are equal. It also predicts an inverted hierarchy for the
neutrino masses. We point out several advantages and distinguishing tests of
the scaling hypothesis compared to the L_e - L_mu - L_tau flavor symmetry,
which is usually assumed to provide an understanding of the inverted hierarchy.
Scenarios which have initially vanishing U_{e3} and maximal atmospheric
neutrino mixing are shown to be unlikely to lead to non-maximal theta_{23}
while keeping simultaneously U_{e3} zero. We find a peculiar ratio of the
branching ratios mu -> e gamma and tau -> e gamma in supersymmetric seesaw
frameworks, which only depends on atmospheric neutrino mixing and results in
tau -> e gamma being unobservable. The consequences of the scaling hypothesis
for high energy astrophysical neutrinos at neutrino telescopes are also
investigated. Then we analyze a seesaw model based on the discrete symmetry D_4
times Z_2 leading to scaling in the low energy mass matrix and being capable of
generating the baryon asymmetry of the Universe via leptogenesis. The relevant
CP phase is identical to the low energy Majorana phase and successful
leptogenesis requires an effective mass for neutrinoless double beta decay
larger than 0.045 eV.
