Data Computed By Dividing The Output By The Number Of Days Worked, To Obtain The Average Production Per Day, And Then Multiplying The Quotient By 303.5 Days, The Potential Number Of Working Days In A Full Year In The Anthracite Region. The Result Includes The Full-Year Capacity Of New Mines, Regardless Of When During The Year They Were Opended And Is Therefore Above The Mean Capacity For The Year. Source: Data For 1890-1930: Brookings Institute, America'S Capacity To Produce, Pp. 550-551; Data For 1931: Mineral Resources, 1931, Pt. Ii, P. 425; Data For 1932-1940: Minerals Yearbook, 1932 And Following Annual Issues.
This NBER data series a01164 appears on the NBER website in Chapter 1 at http://www.nber.org/databases/macrohistory/contents/chapter01.html.
NBER Indicator: a01164
Release: NBER Macrohistory Database
National Bureau of Economic Research, Anthracite Coal Calculated Capacity At 303.5 Days Including New Mines for United States [A01164USA448NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A01164USA448NNBR/, July 4, 2015.