Definition: Indirect volume comparison
Purchasing power parities
A volume comparison between two countries made by dividing the expenditure ratio by the price ratio. The indirect volume comparison between country A and country B for product I is (PIA QIA / PIB QIB) / PIA/PIB = QIA / QIB where the P’s are the prices and the Q’s the volumes (quantities) of the product. Volume comparisons are usually made indirectly.
Eurostat, Organization for Economic Cooperation and Development (OECD), "Eurostat-OECD Methodological Manual on Purchasing Power Parities", Publications Office of the European Union, Luxembourg, 2012