Some aspects of causal relationships

Of the many relationships or associations discovered empirically between economic variables, some may seem to be special or deep in some sense. These special relationships require a distinctive name and "causal" is a convenient one, although it does have plenty of baggage and history associated with it. Proponents of different definitions cannot agree on the basic properties required of a casual relationship. In the paper being discussed, G-causality is used together with an invariance property, which essentially says that the same causality is found under a variety of situations, including several policies.