According to Professor Nick Seybert and his colleagues who studied 605 CEO's on a decade's worth of annual reports from nearly 400 S&P 500 companies, signature size does matter.
"Large signatures - which have been linked to narcissistic personality traits such as dominance and outsize ego - were positively associated with overspending, lower returns on assets, and - paradoxically - higher CEO pay relative to that of industry peers."
The complete article can be found here: http://hbr.org/2013/05/size-does-matter-in-signatures/
Wow. A very interesting study. Yet another reason to choose EQ over Ego. Check out your own signature and see how you compare. Here is mine: