An important source of price statistics in international economic comparisons are the so-called "purchasing power parities" (PPPs). PPPs tell us how many currency units a certain amount of goods and services costs in different countries. PPPs can thus be used to create meaningful indicators that are necessary for cross-country comparisons and that truly reflect differences in purchasing power. They are calculated from an internationally comparable basket of goods and services and used as indicators of price level differences between countries. Thus, if the price level index is above 100, the country in question is "more expensive"; if the price level index is below 100, it is "cheaper" than the country with which it is being compared. PPPs are calculated by Eurostat in cooperation with the OECD and in close collaboration with the statistical institutions of currently 37 participating countries in the framework of the European Comparison Programme (ECP).