Federal income taxation discussion question

Question:  There are three types of tax rate structures: (1)progressive rate, (2) proportional rate, and (3) regressive rate. The US Federal income tax system currentlyapplies the progressive tax rate structure. A common controversy is whether the progressive tax rate is the bestapplication for the US. Many believe that the proportional tax rate would be abetter system for the US Federal income tax system. Identify the differences between the threetax rate structures. In your opinion,what structure would be the best structure for the US? Be sure to support youranswer with the advantages of the method you select and the disadvantages ofthe other tax rate structures