Quality adjusted GEKS-type indices for price comparisons based on scanner data

A wide variety of retailers (supermarkets, home electronics, Internet shops, etc.) provide scanner data containing information at the level barcode, e.g. Global Trade Item Number (GTIN). As complete transaction information, we may use expenditure shares items as weightsfor calculating price indices lowest (elementary) aggregation. The challenge here is choice index formula which should be able to reduce chain drift bias and substitution bias. Multilateral methods seem best due dynamic character data. These work on a wholetime window are transitive, key elimination effect. Following what called an identity test, however, it expected that even when only prices return their original values, becomes one. Unfortunately, commonly used multilateral (GEKS, CCDI, GK, TPD, TDH) do not meet test. paper discusses proposal two weighted versions. On one hand, design proposed based idea GEKS index. other similarly Geary-Khamis method, requires quality adjusting. It shown test most tests. In empirical simulation study, these compared with SPQ index, relatively new also meets analytical considerations well studies confirm high usefulness indices.