Hi Pieter,
I wonder how CasP methods are weakened by the use of indirect measures. In my work, I know that I have to work very hard to substitute for the inability to use measurements of market capitalization, as Hollywood studios are only parts of larger conglomerates.
Take the concept of differential accumulation. In my opinion, it is a concept that is as substantive as the evidence that fills it. Indirect measures are better than nothing, but the concept really shines when it is possible to empirically measure the significance of events — i.e., differential accumulation occurred after X, or in parallel with Y.