I came across one item in a series from the NY Fed on bank complexity – the charts demonstrate an aspect of Banks which we often overlook – that they contain many affiliates as a result of SPVs, or for other commercial purposes. The introduction to the piece says:

Paraphrasing a famous Supreme Court opinion: “I know bank complexity when I see it.” This expression probably speaks to the truth that, if we look at a given banking organization, we ought to be able to state whether it is more or less “complex.” And yet, such an approach hardly offers any guidance if one wants to understand the intricacies of global banks and to monitor and regulate them. What should be the appropriate metrics? It seems to us that there is not a consensus just yet on what complexity might mean in the context of banking. The global dimension of a bank adds many layers, so focusing on global banks is bound to yield a more comprehensive take on the issue than examining purely domestic banking entities. Therefore, in this piece, we view complexity through the lens of the operations of global banks. 

To read more click on over to http://libertystreeteconomics.newyorkfed.org/2014/03/measuring-global-bank-complexity.html