Indexing prices: prices and the fingers of the invisible hand

Chapter 1 starts from the etymology of the term “digital” (from digitus, finger or toe) and shows that the display of prices in retail settings surprisingly rests on a digitalization process right from the beginning. The chapter focuses on a crucial and transitional period: the move from coded to open prices in retail stores in the early twentieth century. The chapter details how and why the grocery business went from concealed, coded prices to open, public and “indexed” prices, that is, prices referred to a given set of numbers but also retailers point at prices, as if they were showing them with their index finger. It explains how this shift was made by means of sophisticated (hand)writing devices and elaborate writing methods. All in all, the chapter traces how the fingers of the invisible hand progressively and ceaselessly moved to rewrite the big book of the contemporary market economy.