The problem is when the execs start feeling like they will never be caught - or worse, when they start tricking themselves into thinking that what they're doing isn't fraud.
Sure, they'll be caught eventually and punished, but the damage is done.
Make all the top level execs liable. That way, one will watch the other and the odds of all of them entering deliberate fraud (or tricking themselves into it) is reduced.
It was also suggested on this thread that a carrot-and-stick (fines for the less compliant, tax reduction for the more compliant) would be pretty clever.
You will never legislate away corruption no matter how high the penalty or how onerous the regulations. The goal is to achieve an acceptable level of corruption with minimal interference on the good guys. It actually reminds me of the questions that DRM raises.
The only hammer I could imagine. Board of directors members would be liable to minority share holders if they allow chief executives to collect sufficiently high compensation that it diminishes the company's profits + punitive damages if it involves conflict of interest.
There, you have a mechanism for private individuals to suing companies and directory for siphoning profits away from the business and essentially force officers and directors to think long terms.
I don't know if this would work but it seems better than any scheme I've heard.
Sure, they'll be caught eventually and punished, but the damage is done.