We wish to thank Georg Hasenkamp for valuable comments on an earlier draft of the manuscript and Steven Diamond for his kindness in reading the manu- script and providing advice regarding the style of the exposition. We are also grateful to Miss Ingeborg Kasper for her careful typing of the manu- script. Contents 1. Introduction 4 2. Price Indices Depending only on Prices 2. 1 Definition, Examples, Implications 4 2. 2 Characterizations of Pri e Indices...