The principle is very simple. When the average of the consumer price index rises or falls by 2.5% over the course of the previous half year, earnings are in principle adjusted by the same proportion. This index and its impact on the salary escalator are published monthly by Luxembourg’s national institute of statistics and economic research, Statec. To conduct a thorough calculation, Statec uses a European methodology and compiles a sample of goods and services that is representative of household consumption. These goods and services, numbering approximately 8,000, are collected into 255 categories or aggregates (or index positions). A weighting coefficient, corresponding to the relative importance in households’ total spending, is then assigned to each aggregate. Since 1999, the list of these items and their weighting has been adjusted every year to take into account changing consumer spending habits.