[alexmingoia]

A regressive tax is one which everyone pays the same regardless of income. Sales tax is a regressive tax. Property tax is a regressive tax.

A flat percentage income tax is progressive. The more one earns, the more they pay. If the flat tax is 15%, someone who earns a million pays $150,000, and someone who earns $30,000 pays $4,500. The richer someone is, the more they would pay.

A flat percentage income tax on all income from all sources is progressive, fair, and simple.

[copperx]

Your logic is faulty.

Using your reasoning, sales and property taxes are also progressive, because wealthy people purchase significantly more goods and properties, which are frequently more expensive than a middle class person would buy. Thus, the rich end up paying more taxes.

[alexmingoia]

Using my logic, tax assessments that don’t change based on income are regressive, and tax assessments that do are progressive. It’s not complicated, and it’s a widely used definition.

https://en.m.wikipedia.org/wiki/Progressive_tax

You may think a flat income tax rate isn’t progressive enough, but it’s not a regressive tax.

[Zanni]

It's still regressive because the utility of money isn't constant. A dollar is worth more to someone with less money.

[alexmingoia]

The utility of money cannot be made constant with a tax, so I’m not sure what you consider the distinction between a regressive and progressive tax?