Anomaly-Free Flavor Symmetry and Neutrino Anarchy
  We show that one can describe the quark and lepton masses with a single anomaly-free U(1) flavor symmetry provided a single order one parameter is enhanced by roughly 4-5. The flavor symmetry can be seen to arise from inside the $E_6$ symmetry group in such a way that it commutes with the SU(5) grand unified gauge group. The scenario does not distinguish between the left-handed lepton doublets and hence is a model of neutrino anarchy. It can therefore account for the large mixing observed in atmospheric neutrino experiments and predicts that the solar neutrino oscillation data is consistent with the large mixing angle solution of matter-enhanced oscillations. 
M. S. Berger and Kim Siyeon