In the paper the solution behaviour of a class of parameter-dependent
quasi-variational inequalities is analysed. By using sensitivity and s
tability results for monotone variational inequalities and the Implici
t Function Theorem of F. H. Clarke, we derive conditions under which t
he perturbed solution of a parametric quasi-variational inequality is
locally unique, lipschitzian and directionally differentiable. These r
esults are particularized in the case of parametric implicit complemen
tary problems.