  We use a recently proposed model of the interplane conductivity of high
temperature superconductors to investigate the `scattering rate sum-rule'
introduced by Basov and co-workers. We present a new derivation of the
sum-rule. The quantal and thermal fluctuations of the order parameter which
have been argued to produce the observed pseudogap behavior are shown to
increase the total integrated `scattering rate' but may either increase or
decrease the `quasiparticle' contribution from frequencies greater than twice
the superconducting gap.
