A 4% consumption tax wouldn't be nearly enough to maintain current tax revenues. And consumption taxes are highly regressive; the poor have to spend almost all their income on consumption.
Consumption would include all money exchanged. If you invest in the stock market for example $ paid to broker, and money invested would be taxed as it leaves your hand. When you pull it back, broker/investment firm pays the consumption tax because it's leaving them, going back to you.
Anything a company pays money for goes to consumption including: Wages, Power bill, Land, Buildings, Planes, Trains, Transportation of Goods.
Poor would be offset by guaranteed basic income and universal healthcare. GBI would basically be a negative income tax, the 4% is variable and can be raised/lowered yearly whether the country's in the black/red - but only 1-2 points per year w/ congress's approval. Also 4% was just a number I pulled out of ass, could be 7 or 8% instead.
I don't see how poor would suffer under this if they have a guaranteed 30-40k income if they don't work one day the entire year. Sure they might spend all of that back in food, tax, shelter, etc..but they have food, and shelter which they may not have had before.
The only stipulation on GBI would be you must have a residence to collect. (If you want to remain homeless and spend all cash on Meth, that won't work, you need to at least get housing).
there could be a land/resource tax on top, for property owners. If you own land > $200k in value, you'd pay a specific tax on the land, if you use resources you pay a tax on that on-going including:Water, Coal, Natural Gas, Oil - if it comes from the earth, it'd be taxed.
I've heard of schemes that involve fully paying for GBI using ONLY land/resource taxes, but I think that wouldn't be enough to pay for things. But we don't need a military as big as we have, there's lots of places we can cut corners and spend less money.
WE need to explore our budget and use tech to lower costs across the board as much as possible and streamline things.