Purchasing power parities and the Dollar-A-Day approach: An unstable relationship

Abstract

We show that the Dollar-A-Day methodology in global poverty measurement provides inconsistent International Poverty Line (iPL) solutions when a complete set of consistency criteria in the iPL definition is used. This article illustrates that minor fluctuations in purchasing power parity exchange rates can yield inconsistent iPLs. We find a rate of inconsistency of 46.1% and we conclude that this is a worrisome attribute of the method.