Data Include Switching And Terminal Companies Until 1933. Source: Computed By NBER From Series (Total Hours Worked Per Month, All Employees On Hourly Basis) And (Total Number Of Employees On Hourly Basis).
This NBER data series m08154 appears on the NBER website in Chapter 8 at http://www.nber.org/databases/macrohistory/contents/chapter08.html.
NBER Indicator: m08154
Release: NBER Macrohistory Database
National Bureau of Economic Research, Total Hours Worked Per Month, Per Employee, All Employees On Hourly Basis for United States [M08154USM065NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M08154USM065NNBR/, August 29, 2015.