  We consider one component lattice gases with a local dynamics and a
stationary product Bernoulli measure. We give upper and lower bounds on the
diffusivity at an equilibrium point depending on the dimension and the local
behavior of the macroscopic flux function. We show that if the model is
expected to be diffusive, it is indeed diffusive, and, if it is expected to be
superdiffusive, it is indeed superdiffusive.
