We study the metric introduced by Pli´s on the set of convex
closed bounded subsets of a Banach space. For a real Hilbert space
it is proved that metric projection and (under certain conditions) metric
antiprojection from a point onto a set satisfy a Lipschitz condition with
respect to the set in the Pli´s metric. It is proved that solutions of a broad
class of minimization problems are also Lipschitz stable with respect to the
set. Several examples are discussed.