General Man-Hour Costs
of
Various Commodities

(Updated August 2016)

Time required to till soil for Farming

Hand Spade: 96 man-hours/acre
Animal drawn Plow:
16 man-hours/acre
Single-Bottom Plow (1855): 8 man-hours/acre
60-disc Tractor Plow (1934): 0.088 man-hours/acre

Notes: Calculated from three sets of quotes:

1) “the American and European farmer had improved but little upon the ancient Roman method of spading the soil, an operation that required 96 man-hours to till one acre”
2.) “The change is best illustrated by comparative figures showing the number of men that would be required under the different methods to till the soil for the production of the 1928-29 yield of wheat in the United States. Here are the figures:
By the ancient method of spading...........6,000,000 men
With ox-drawn plows........................1,000,000 men
With Oliver single-bottom plow of 1855.......500,000 men
With modern 60-disc tractor plow...............4,000 men”
3.) “Today we have on the large farms of the west the tractor-drawn, 60-disc or duckfoot plow which reduces the man-hours per acre to the decimal fraction of an hour, .088, or about five minutes to the acre.”

Reference:
Unemployment and the Machine (Chapter 6, specifically) by the Industrial Workers of the World (IWW), 1934

Time required to produce one Automobile (USA)

1904: 1,291 man-hours/car
1919:
313 man-hours/car
1929: 92 man-hours/car
1979: 80.3 man-hours/car (Japanese) vs 144 man-hours/car (US) [2]

Reference:
Engineering: Its Role and Function in Human Society edited by William H. Davenport, Daniel I. Rosenthal (page 96)
[2] Costs and Productivity in Automobile Production: The Challenge of Japanese Efficiency, Page 47

Time required to produce one ton of Steel (USA)

1900: 70 man-hours/ton
1929: 13 man-hours/ton
1982: 10 man-hours/ton (US Steel) [2]
1987: 3.8 man-hours/ton (US Steel) [2]

Reference:
Engineering: Its Role and Function in Human Society edited by William H. Davenport, Daniel I. Rosenthal (page 96)
[2] Annual Survey Concerning Competitive Conditions in the Steel Industry and Industry Efforts to Adjust and Modernize (USITC Pub 2115, Sep 1988)