  In [15] the authors proved the Pugh-Shub conjecture for partially hyperbolic
diffeomorphisms with 1-dimensional center, i.e. stable ergodic diffeomorphism
are dense among the partially hyperbolic ones. In this work we address the
issue of giving a more accurate description of this abundance of ergodicity. In
particular, we give the first examples of manifolds in which all conservative
partially hyperbolic diffeomorphisms are ergodic.
