  We study the observed correlations between the duration and luminosity of the
early afterglow plateau and the isotropic gamma-ray energy release during the
prompt phase. We discuss these correlations in the context of two scenarios for
the origin of the plateaus. In the first one the afterglow is made by the
forward shock and the plateau results from variations of the microphysics
parameters while in the second one the early afterglow is made by a long-lived
reverse shock propagating in a low Lorentz factor tail of the ejecta.
