  We discuss the charge distributions across the bulk of a two-dimensional
electron gas system which is on an integer or fractional quantum Hall plateau.
Our analysis is based on a relation, derived from the long wavelength limit of
the bulk density-density response function, between the induced charge and
leading derivatives of a slowly varying Hall potential. We use the Wiener-Hopf
method to solve the coupled response and Poisson equations. Unlike the integer
case, treated in previous work, the induced charge in the fractional case can
alternate in sign.
