There are a few imprecisions among Steve Kates's claims.

Haberler was NOT hired by the League in 1930. He was contacted at the  
beginning of December 1933, and started working in Geneva on 1 March  
1934.

He could therefore not have published in 1935 (in spite of having  
proceeded prodigiously swiftly). By August of that year he had  
managed to write a first draft of the analysis of theories (50 pages  
typescript), which he elaborated into a much bigger typescript by  
June 1936. The final version was published, under much pressure by  
the League for accelerating the editing (meanwhile Haberler had moved  
to Harvard and was held up by his new commitments).

Moreover, the purpose of the book was not that of dealing with ALL  
the business cycle theories that had been produced, but only those  
current at his time. This is explicitly stated.

Haberler's statement cited by Kates was pronounced in very similar  
terms by Aftalion and espeially Mitchell, both in 1913--the only  
missing term being "complete unanimity", but the substance is the  
same; Mitchell uses the expression "substantial agreement". The  
critical target of Haberler, and Mitchell and Aftalion and scores of  
other writers before them, beginning (at least) from J.-E. Briaune in  
1840 and passing from Coquelin, Juglar, Mills, Jevons etc., was the  
earlier approach to crises, which focused on crises taken in  
isolation rather than as a succession of related events, which was  
the 'classical' (and mainstream until the end of the XIX century)  
approach to economic disturbances.

Daniele Besomi