Purchasing power standard is an artificial common reference currency unit used in the European Union which eliminates the differences of price levels between countries. So, a PPS allows to buy the same volume of goods and services in all the countries. This unit allows significant comparisons in volume of economic indicators between countries. The aggregates expressed in PPS are calculated by dividing the aggregates expressed in current prices and in national currency by the Purchasing Power Parities (PPP).
The uncertainty level characterizing prices and basic data of national accounts as well as the methods used to calculate the PPA involve that the differences between countries having a quasi similar index do not have to be sur-interpreted.