Intro
William F. Buckley argued for a flat marginal income tax rate from a fairness position: we get benefits from society proportional to our income, so we should contribute to the maintenance of society proportional to our income. Besides that, a flat rate is simpler, and supports other tax simplification.That said, a flat marginal rate doesn't require everybody pays the same net rate, but the only way to get progressive taxes with a constant marginal rate is to have the government giving individuals money at the bottom rung. I had this idea long ago, but thought the payments at the bottom would be too radical. Apparently the "Basic Income" idea is catching on, so it's time to publish!
Example
This is more clear with an example. I'll chose a marginal rate of 39.6% (the current US top marginal rate), a payment of $11,490 (the US individual poverty line), and no individual exemption (vs the current US $6100). Somebody earning nothing gets $11,490, clearly. Individuals earning up to $29,015 get more back than they pay in because 39.5% of $29,015 is $11,490. Somebody earning $50,000 would pay $19,800 in taxes and get $11,490 back, for a net payment of $7,310, a bit more than the current $6,986. Somebody earning $100,000 pays a net $28,110, somewhat more than the current $19,760.The specific value for the basic subsidy can be set lower or higher depending on how progressive we want the taxes to be; the tax rate should be adjusted to be revenue neutral. My example (starting with the poverty line) allows us to replace basic welfare entirely, but the opposite extreme of no basic income is obviously less progressive than our current system.
Advantage of a fixed rate to tax collecting
Here's another radical idea that's enabled by a flat tax rate: put banks (instead of employers) in charge of collecting income taxes. We'd have two kinds of accounts: pre-tax and post-tax. Paychecks go into pre-tax accounts; taxes are withdrawn when the money is transferred to a post-tax account. Checks (or other debits) drawn against a pre-tax account can be deposited in other pre-tax accounts, e.g. long-term investments; this allows all savings to enjoy tax-free growth, like IRAs and 401Ks do today. Checks from a pre-tax account can be cashed by registered charities and anybody else we want to designate as able to receive tax-free payments.
We could require checks for services to be marked as such, and thus only legally depositable in a pre-tax account. That doesn't eliminate the underground, untaxed economy, but it requires both parties to participate in the cheating.
The net effect of this, besides further simplification, is to switch taxes from earning to spending, which is also a good thing.
We could require checks for services to be marked as such, and thus only legally depositable in a pre-tax account. That doesn't eliminate the underground, untaxed economy, but it requires both parties to participate in the cheating.
The net effect of this, besides further simplification, is to switch taxes from earning to spending, which is also a good thing.
Arguments for Basic Income
Since Basic Income is already a thing, there are already plenty of arguments out there for it. See for instance the current campaign to pass it in Switzerland. For me, it comes down to each of us deserving basics of life such has food, shelter, and clothing. We can give those out directly, e.g. with food stamps and subsidized housing, but it's much more respectful and efficient to give people the resources to get those things themselves.
So, why do we give any money to those who already earn enough for the basics? From an economic standpoint, it's to give people "on support" incentive to go out and earn whatever they're capable of. From a moral standpoint, it's because the poor deserve the extra luxuries that their extra income buys them as much as the rich do!
