  The edge states in the integer quantum Hall effect are known to be
significantly affected by electrostatic interactions leading to the formation
of compressible and incompressible strips at the boundaries of Hall bars. We
show here, in a combined experimental and theoretical analysis, that this does
not hold for the quantum Hall effect in narrow graphene ribbons. In our
graphene Hall bar, which is only 60 nm wide, we observe the quantum Hall effect
up to Landau level index k=2 and show within a zero free-parameter model that
the spatial extent of the compressible and incompressible strips is of a
similar magnitude as the magnetic length. We conclude that in narrow graphene
ribbons the single-particle picture is a more appropriate description of the
quantum Hall effect and that electrostatic effects are of minor importance.
