\frac{\displaystyle{\langle \theta \rangle }}{\displaystyle{M}}\right) ^{n}  \label{one}$$where $\psi$ and $\psi^c$ denote quark/lepton superfields, $H$ is a Higgs superfield, $M$ is the heavy messenger mass corresponding to the intermediate state in the Froggatt-Nielsen mechanism and $\langle \theta
\rangle $ is the familon vev that breaks $G_{F}$ such that $\langle \theta
\rangle /M$ is a small expansion parameter [@froggatt]. In the following, we do not specify the family group or the exact mechanism of symmetry breaking as our conclusions are equally applicable to (Abelian or non-Abelian) flavour theories generating a given structure in the Yukawa couplings [@flavth].

The generation of Yukawa couplings (or other holomorphic couplings in the superpotential) though non-renormalisable operators is not the only effect of integrating out the heavy fields in the low energy effective theory. It is well known that the non-holomorphic couplings involving the kinetic terms and gauge couplings also receive corrections from the flavour breaking terms. This implies a non canonical Kähler potential, different from the identity in flavour space. In determining the physical implications of the theory it is much simpler to work in a theory with canonical kinetic terms and this can be done by choosing a linear combination of the chiral superfields such that 