  Entangled states are notoriously non-separable, their sub-ensembles being
only statistical mixtures yielding no coherences and no quantum interference
phenomena. The interesting features of entangled states can be revealed only by
coincidence counts over the (typically) two sub-ensembles of the system. In
this paper we show that this feature extends to properties thought to be local,
for example the transmissivity coefficient of a beam splitter. We discuss a
well-known experimental setup and propose modifications, so that delayed-choice
can be added and this new feature of entanglement tested.
