Compare a CMO with A, B, Z to a CMO that has the same tranches but is backed by a larger pool of mortgages (and therefore has a residual). In a CMO with a residual: Tranche A has a shorter duration and less inflationvinterest rate risk Tranche B has a shorter duration and more inflationlinterest rate risk Tranche B has a longer duration and more inflationinterest rate risk Tranche Z has more inflationinterest rate risk Tranche Z has less inflationinterest rale risk