A big +1 for this!
We should even concider using a system like we have in the Netherlands:
Income tax is devided into 4 'layers'
Layer1 € 0 u/i € 19.822 36,50%
Layer 2 € 19.822 u/i € 33.589 42%
Layer 3 € 33.589 u/i € 57.585 42% (yes, again 42%, the rates change every year, and they happen to be the same this year)
Layer 4 € 57.585 or more 52,00%
You pay 36.5% over the first €19.822 income.
Anything you earn more than 19.822 is charged 42%, up till €33.589
Anything you earn more than 33.589 is charged 42% up till €57.585
Anything you earn more than 57.585 is charged with 52% tax
Due to this system, the 'big earners' pay more tax because they have more to spare and earn enough already
Well, US' taxable income work in a... Different way, especially due to the economic system differences and the amount of time the federal (which isn't federal) bank has existed, also due to the other large influences such as the well known national debt and the actual inflation. Here's a link concerning the current maximum taxable income, even though I'm more than positive that different business types (sole business, corporations and their different types, partnerships) have different taxation plans, I'm sure more can be found with a more dedicated and thorough search.