[recursive]

Maybe proportional to revenue (not profit).

Plus standard baseline?

[Nasrudith]

Revenue, while it would solve the fact that profit-taking vs reinvestment is arbitrary there are other flaws. For one that would make it disproportionately ruinous on low margin businesses. If the fix was so simple I suspect that we would see it tried in more places.

[recursive]

I don't think it's just simplicity. It's probably also contrary to the interests of some of the law-makers' biggest donors.