While putting things back in the file cabinet, I discovered that I had made
the scholar's basic error -- an incomplete cite:  Here it is more fully.
The TNEC report on concentration of economic power relevant to our interest is
Monograph No. 43: THE MOTION PICTURE INDUSTRY -- A PATTERN OF CONTROL.  It runs
92 pages and details the considerations that led eventually to divorcement and
reorganization of the industry.