electrification mass production productivity
The first three decades of the 20th century saw economic output surge with electrification, mass production, and motorized farm machinery, and because of the rapid growth in productivity there was a lot of excess production capacity and the work week was being reduced. The dramatic rise in productivity of major industries in the U.S. and the effects of productivity on output, wages and the workweek are discussed by Spurgeon Bell in his book Productivity, Wages, and National Income (1940).
