This third principle may be especially important today because, in my view, there is an important disparity between the balance between supply and demand in the labor and product markets, with at least a hint of excess demand in labor markets, but very little to suggest such imbalance in product markets.
It is important to understand that the Phillips Curve is a model of inflation dynamics, not a model that determines the equilibrium inflation rate. For this reason, the Phillips Curve paradigm is not at all inconsistent with the view that inflation is, in the long run, exclusively a monetary phenomenon.