Data Cover Manufacturing Companies With Assets Over $15 Million. Source: G.H. Moore, Business Cycle Indicators, Vol. 2, NBER, P. 159 (National Industrial Conference Board Data)
This NBER data series q16088 appears on the NBER website in Chapter 16 at http://www.nber.org/databases/macrohistory/contents/chapter16.html.
NBER Indicator: q16088
Release: NBER Macrohistory Database
National Bureau of Economic Research, Diffusion Index, New Capital Appropriations, 500 Manufacturing Companies, Four Quarter Span for United States [Q16088USQ509NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/Q16088USQ509NNBR/, July 5, 2015.