[twblalock]

By what standard, other than tax law, can the fair amount of tax be determined?

[AnimalMuppet]

By some assumed standard of morality. "Fair" tax can never be determined by tax law - only "legal" can be determined that way.

[kazinator]

There exists a fair tax: the user fee. Pay for what you use. (But then we are still reduced to bargaining over what is a fair price).

Insurance is also a form of fair tax, when premiums are based on claim history and objective risk factors, and the market is reasonably competitive.