As research has shown, would the full Billion Prices Project data have been available in 2008, the turning point in US inflation following the demise of Lehman Brothers could have been identified months before it showed up in the official US consumer price Index.14 Online prices are, however, only one source of potential interest for policymakers.
Large-scale barcode scanner data, for example, are an alternative avenue that researchers at the ECB have explored in the past to investigate factors that determine prices and the degree of price dispersion, much in the tradition of our long-standing efforts under the umbrella of the Eurosystem Inflation Persistence Network.15 The data, which consist of 3.5 million observations on the price and quantity of individual products sold, have confirmed that competition at producer and retail level is a key factor affecting micro price-setting.