  We study the effects of renormalization due to hidden-sector dynamics on
observable soft supersymmetry-breaking parameters in the minimal supersymmetric
extension of the Standard Model (MSSM), under various hypotheses about their
universality at a high input scale. We show that hidden-sector renormalization
effects may induce the spurious appearance of unification of the scalar masses
at some lower scale, as in mirage unification scenarios. We demonstrate in
simple two-parameter models of the hidden-sector dynamics that the parameters
may in principle be extracted from experimental measurements, rendering the
hidden sector observable. We also discuss the ingredients that would be
necessary to carry this programme out in practice.
