The dominant eigenvalue and the corresponding eigenvector (or Perron v
ector) of a non-linear eigensystem are considered. We discuss the effe
cts upon these, of perturbations and of aggregation of the underlying
mapping. The results are applied to study the sensivity of the outputs
in a non-linear input-output model. For that purpose, it is shown tha
t the input-output model can be rewritten as a non-linear eigensystem.
It turns out that the Perron vector of this eigensystem includes the
solution vector of the input-output model.