Purchasing power parity and the theory of general relativity: the first tests

We implement novel tests of general relative purchasing power parity (PPP), defined as a long-run unit elasticity of the nominal exchange rate with respect to relative national prices, allowing for potentially permanent real exchange rate shocks. The finite-sample properties of the estimators used are analyzed through Monte Carlo analysis, allowing for country heterogeneity, cross-sectional dependence and non-stationary disturbances. Application to panel data sets of industrialized and developing economies reveals that inflation differentials are on average reflected one-for-one in long-run nominal exchange rate depreciation-i.e. that general relative PPP holds.