Energy conservation and the constitutive relations in chiral and non-reciprocal media

We consider the possibility that the chirality parameters and the non-reciprocity parameters appearing in the constitutive relations for the displacement and magnetic induction fields in a biisotropic medium might not be equal and thereby shed light on the physical significance of the fact that they are the same. We find, in particular, that they must be equal in order to retain the local conservation of energy.