  We examine a paradox, suggested by Banks and Dabholkar, concerning
nonperturbative effects in an effective field theory which is obtained by
integrating out a generation of heavy fermions, where the heavy fermion masses
arise from Yukawa couplings. They argue that light fermions in the effective
theory appear to decay via instanton processes, whereas their decay is
forbidden in the full theory. We resolve this paradox by showing that such
processes in fact do not occur in the effective theory, due to matching
corrections which cause the relevant light field configurations to have
infinite action.
