If you really think 'x' is important, you'll...

spend more time on it?

Wouldn't really have thought so.

Take your brain (please! take it!):

Like your brain, the R&D department is part of a complex system that does a lot of important stuff. You can argue that the R&D department is the most important part of a company, not least because it couldn't survive long without it. I think the same thing about my brain--but I'd still be just as dead without my liver. You certainly can't prove anything about my effectiveness as a journalist by pointing out that it weighs less than my bones.

So how big should a "brain" be? Hard to say. But let's look at some companies that are generally recognized as pretty innovative, and their R&D as a percentage of revenue:

Apple: three cents out of every dollar

Google: ten cents out of every dollar

Intel: fifteen cents out of every dollar

Genzyme (innovative biotech startup!): sixteen cents of every dollar

US Government: three cents out of every dollar

The article's here, with links that back up those figures. By Megan McArdle.