I would like to see a definite cite/quote from Frisch on this.  He 
certainly used the term "macrodynamic" at the 1933 Econometric Society meetings,
however this term had been used earlier in the 1931 Polish version
of a paper by Michal Kalecki that was later translated into French and then 
was published in English in 1935 in Econometrica, "A macrodynamic theory of 
business cycles," 1935 3, 327-344.  OTOH, Paul Samuelson claimed in his 1997 
JEP piece on "Credo of a lucky textbook author," 11(2), 153-160, that the first
to use the term in English without a hyphen was Erik Lindahl in his 1939 
Studies in  the theory of money and capital.
However, the second part of that originally was published in Swedish in 1930 
as Penningpolitikens medel, (The means of monetary policy), and it may have
first appeared there.

Barkley Rosser