Us federal income tax is progressive by law, but which best explains why is it sometimes regressive in practice?

I think you forgot to give the options along with the question. I am answering the question based on my knowledge and research. "High-income earners reduce their tax rates through numerous deductions" best explains why is it sometimes regressive in practice. I hope that the answer has come to your desired help.

Via:   "if you are found to be supplying or dealing drugs, the punishment is likely to be tough. supplying drugs doesn’t just apply to dealers. if police suspect that you intend to share drugs with your friends, this is still considered to be supplying.

being suspected of supplying drugs means you are much more likely to be charged. the amount of drugs found on you, and whether you have a criminal record, will be taken into account when a punishment is being decided.

decisions to prosecute are taken by the public prosecution service. the maximum sentences for intent to supply drugs are:

- up to life in prison or an unlimited fine (or both) for a class a drug- up to 14 years in prison or an unlimited fine (or both) for a class b or class c drug."sorry if this was a school question, you didnt supply options so i assumed it was a personal question, which if it is, reconsider selling or having possesion of any drugs at all. i wish you the best!