When F&S published their Monetary History in 1963, their position was quite an isolated one (although of 1  2  Without associating them with the opinions expressed here, I would like to thank Emilia Bonaccorsi di Patti, Giuseppe Ferrero, Stefano Pietrosanti and Alessandro Secchi for helping me to write this speech, as well as Paolo Angelini, Sergio Nicoletti Altimari and Ignazio Visco for their reading and comments.
Even where the data can be perfectly measured there is often discrepancy between the economic concept that we would want to measure and the real phenomenon that the statistics attempts to measure. For example Gross Domestic Product seeks to measure the total economic activity, the value added that takes place in the economy over time. It is almost impossible to measure this directly.