We show the importance of a dynamic aggregation bias in accounting for the PPP puzzle. We prove that established time-series and panel methods substantially exaggerate the persistence of real exchange rates because of heterogeneity in the dynamics of disaggregated relative prices. When...

This paper (i) proposes a simple multi-currency model of speculative foreign exchange (FX) trading, (ii) uses a natural experiment to identify the implied components of the optimal trading strategy, and (iii) proposes a new spectral inference method to strengthen the statistical evidence on the...