At present, both consumption and earnings are subject to taxation (in most cases). And as both are structured presently, consumption taxes are regressive and earnings taxes are progressive.
Which method of taxation do you think is better/fairer and why?
I don't care about regressive or progressive at all. What I care about are your personal freedoms and how the income tax takes them away.
Consider:
In order to tax income, the fed must know (down to the penny) how much and what types of income you have brought in. They do this by forcing you to disclose what is essentially your own private business. And, just to be sure that you are not lying they will verify that via the employers reports as well as mandatory reporting from investment managers etc.
You are not only required to disclose your personal finances, but your own personally identifiable information goes in the pot as well.
With identity theft the newest kid on the up and coming crimes block.... all you need is to envision an IRS employee who desires to make some major cash.
They know who you are, who you are married to, your kids names/birthdays/ssn's, they know where you work and about how long you've been there. By simply graphing your w2 from that employer they can tell if you have been promoted or stagnated.
They know the average property values and annual incomes of you and everyone else on the block. Don't drive an escalade that is "above your means" unless you want to meet an auditor.
Tax court isn't structured like criminal court. You must prove you are innocent. Your assets can be seized without full and proper due process. And even if Perry Mason is your best friend, only certain attorneys are even allowed to sit in the court as official counsel.
The income tax system makes a mockery of the concept of individual privacy, the ideal that all men are created equal, and that funding the government is everyone's duty.
A consumption tax or sales tax is more to my liking since most, not all, purchases are anonymous as you slip out the check stand at Walmart.
Almost every state in the union has a sales tax. This eliminates the need for the majority of the IRS. Just have the states collect and remit. Let them keep half a percent for their additional bookeeping.
Everyone, rich/poor, legal/illegal, citizen or tourist, doctor or on-the-street drug dealer, or black/white/pink/green all pay the same rate. Yes, the poor will spend a higher percentage of income in this tax. So what? I work in some of the poorest parts of town. I install satellite TV's. Nowadays poor means you have the best and latest Nike Air (fill in the current name) on your feet. Poor means you drive a beater car with rims and a stereo that exceed four figures. Poor means you still have a cell phone, cable tv, air conditioning, enough to eat to the point of obesity, and pocket money for beer and smokes. So please excuse me for not being 100% sympathetic to the whole "regressive" sin of a sales tax.
Government spending is a discussion worthy topic in its' own right. But would be beyond the scope of the OP.