Journal Article Pigou, Industrial Fluctuations Get access Warren M. Persons Warren M. Persons Harvard University Search for other works by this author on: Oxford Academic Google Scholar The Quarterly Journal of Economics, Volume 42, Issue 4, August 1928, Pages 669–677, https://doi.org/10.2307/1882538 Published: 01 August 1928

which is free from the influence of prices. Bank debits, which afford the most general index of business activity, measure the dollar volume of transactions made through checks, and hence reflect the prices of goods, services (i.e., wages in general), and securities, as well as the volume of transactions; whereas most series expressed in physical units, however well they may reflect general movements, actually apply to some particular phase of activity, such as freight shipments or manufacturing.