This paper investigates purchasing-power parity (PPP) since the late nineteenth century. I collected data for a group of twenty countries over one hundred years, a larger historical panel of annual data than has ever been studied before. The evidence for long-run PPP is favorable using recent...

The PPP puzzle is based on empirical evidence that international price differences for individual goods (LOOP) or baskets of goods (PPP) appear highly persistent or even non-stationary. The present consensus is these price differences have a half-life that is of the order of five years at best,...

This paper investigates purchasing-power parity (PPP) since the late nineteenth century for a sample of twenty countries, a broader sample of pooled annual data than has been studied before. Econometric results for time-series and panel samples allows us to test the robustness of the PPP...