Whose tax plan makes the most sense?

JDN 2457496

The election for the President of the United States has now come down to four candidates; the most likely winner is Hillary Clinton, but despite claims to the contrary Bernie Sanders could still win the Democratic nomination. On the Republican side Donald Trump holds a small lead over Ted Cruz, and then there’s a small chance that Kasich could win or a new candidate could emerge if neither can win a majority and they go to a brokered convention (I’ve heard Romney and Ryan suggested, and either of them would be far better).

There are a lot of differences between the various candidates, and while it feels partisan to say so I really think it’s pretty obvious that Clinton and Sanders are superior candidates to Trump and Cruz. Trump is a plutocratic crypto-fascist blowhard with no actual qualifications, and Cruz seems to extrude sleaze from his every pore—such that basically nobody who knows him well actually likes him.

In general I’ve preferred Sanders, though when he started talking about trade policy the other day it actually got me pretty worried that he doesn’t appreciate the benefits of free trade. So while I think a lot of Clinton’s plans are kind of lukewarm, I wouldn’t mind if she won, if only because her trade policy is clearly better.

But today I’m going to compare all four candidates in a somewhat wonkier way: Let’s talk about taxes.

Specifically, federal income tax. There are a lot of other types of taxes of course, but federal income tax is the chief source of revenue for the US federal government, as well as the chief mechanism by which the United States engages in redistribution of wealth. I’ll also briefly discuss payroll taxes, which are the second-largest source of federal revenue.
So, I’ve looked up the income tax plans of Hillary Clinton, Bernie Sanders, Donald Trump, and Ted Cruz respectively, and they are summarized below. The first column gives the minimum income threshold for that marginal tax rate (since they vary slightly I’ll be rounding to the nearest thousand). For comparison I’ve included the current income tax system as well. I’m using the rates for an individual filing singly with no deductions for simplicity.

Current system Hillary Clinton Bernie Sanders Donald Trump Ted Cruz
0 10% 10% 10% 0% 0%
9,000 15% 15% 15% 0% 0%
25,000 15% 15% 15% 10% 0%
36,000 25% 25% 25% 10% 10%
37,000 25% 25% 25% 10% 10%
50,000 25% 25% 25% 20% 10%
91,000 28% 28% 28% 20% 10%
150,000 28% 28% 28% 25% 10%
190,000 33% 33% 33% 25% 10%
250,000 33% 33% 37% 25% 10%
412,000 35% 35% 37% 25% 10%
413,000 39.6% 35% 37% 25% 10%
415,000 39.6% 39.6% 37% 25% 10%
500,000 39.6% 39.6% 43% 25% 10%
2,000,000 39.6% 39.6% 48% 25% 10%
5,000,000 39.6% 43.6% 48% 25% 10%
10,000,000 39.6% 43.6% 52% 25% 10%

As you can see, Hillary Clinton’s plan is basically our current system, with some minor adjustments and a slight increase in progressivity.In addition to these slight changes in the income tax code, she also proposes to close some loopholes in corporate taxes, but she basically doesn’t change the payroll tax system at all. Her plan would not change a whole lot, but we know it would work, because our current tax system does work.

Despite calling himself a social democrat and being accused of being a far more extreme sort of socialist, Bernie Sanders offers a tax plan that isn’t very radical either; he makes our income tax system a bit more progressive, especially at very high incomes; but it’s nothing out of the ordinary by historical standards. Sanders’ top rate of 52% is about what Reagan set in his first tax cut plan in 1982, and substantially lower than the about 90% top rates we had from 1942 to 1964 and the about 70% top rates we had from 1965 to 1981. Sanders would also lift the income cap on payroll taxes (which it makes no sense not to do—why would we want payroll taxes to be regressive?) and eliminate the payroll tax deduction for fringe benefits (which is something a lot of economists have been clamoring for).

No, it’s the Republicans who have really radical tax plans. Donald Trump’s plan involves a substantial cut across the board, to rates close to the lowest they’ve ever been in US history, which was during the Roaring Twenties—the top tax rate was 25% from 1925 to 1931. Trump also proposes to cut the corporate tax in half (which I actually like), and eliminate the payroll tax completely—which would only make sense if you absorbed it into income taxes, which he does not.

Ted Cruz’s plan is even more extreme, removing essentially all progressivity from the US tax code and going to a completely flat tax at the nonsensically low rate of 10%. We haven’t had a rate that low since 1915—so these would be literally the lowest income tax rates we’ve had in a century. Ted Cruz also wants to cut the corporate tax rate in half and eliminate payroll taxes, which is even crazier in his case because of how much he would be cutting income tax rates.

To see why this is so bonkers, take a look at federal spending as a portion of GDP over the last century. We spent only about 10% of GDP in 1915; We currently take in $3.25 trillion per year, 17.4% of GDP, and spend $3.70 trillion per year, 19.8% of GDP. So Ted Cruz’s plan was designed for an era in which the federal government spent about half what it does right now. I don’t even see how we could cut spending that far that fast; it would require essentially eliminating Social Security and Medicare, or else huge cuts in just about everything else. Either that, or we’d have to run the largest budget deficit we have since WW2, and not just for the war spending but indefinitely.

Donald Trump’s plan is not quite as ridiculous, but fact-checkers have skewered him for claiming it will be revenue-neutral. No, it would cut revenue by about $1 trillion per year, which would mean either large deficits (and concomitant risk of inflation and interest rate spikes—this kind of deficit would have been good in 2009, but it’s not so great indefinitely) or very large reductions in spending.

To be fair, both Republicans do claim they intend to cut a lot of spending. But they never quite get around to explaining what spending they’ll be cutting. Are you gutting Social Security? Ending Medicare? Cutting the military in half? These are the kinds of things you’d need to do in order to save this much money.

It’s kind of a shame that Cruz set the rate so low, because if he’d proposed a flat tax of say 25% or 30% that might actually make sense. Applied to consumption instead of income, this would be the Fair Tax, which is 23% if calculated like an income tax or 30% if calculated like a sales tax—either way it’s 26 log points. The Fair Tax could actually provide sufficient revenue to support most existing federal spending,

I still oppose it because I want taxes to be progressive (for reasons I’ve explained previously), and the Fair Tax, by applying only to consumption it would be very regressive (poor people often spend more than 100% of their incomes on consumption—financing it on debt—while rich people generally spend about 50%, and the very rich spend even less). It would exacerbate inequality quite dramatically, especially in capital income, which would be completely untaxed. Even a flat income tax like Cruz’s would still hit the poor harder than the rich in real terms.

But I really do like the idea of a very simple, straightforward tax code that has very few deductions so that everyone knows how much they are going to pay and doesn’t have to deal with hours of paperwork to do it. If this lack of deductions is enshrined in law, it would also remove most of the incentives to lobby for loopholes and tax expenditures, making our tax system much fairer and more efficient.

No doubt about it, flat taxes absolutely are hands-down the easiest to compute. Most people would probably have trouble figuring out a formula like r = I^{-p}, though computers have no such problem (my logarithmic tax plan is easier on computers than the present system); but even fifth-graders can multiply something by 25%. There is something very appealing about everyone knowing at all times that they pay in taxes one-fourth of what they get in income. Adding a simple standard deduction for low incomes makes it slightly more complicated, but also makes it a little bit progressive and is totally worth the tradeoff.

His notion of “eliminating the IRS” is ridiculous (we still need the IRS to audit people to make sure they are honest about their incomes!), and I think the downsides of having no power to redistribute wealth via taxes outweigh the benefits of a flat tax, but the benefits are very real. The biggest problem is that Cruz chose a rate that simply makes no sense; there’s no way to make the numbers work out if the rate is only 10%, especially since you’re excluding half the population from being taxed at all.

Hopefully you see how this supports my contention that Clinton and Sanders are the serious candidates while Trump and Cruz are awful; Clinton wants to keep our current tax system, and Sanders wants to make it a bit more progressive, while Trump and Cruz prize cutting taxes and making taxes simple so highly that they forgot to make sure the numbers actually make any sense—or worse, didn’t care.

Why the Republican candidates like flat income tax—and we really, really don’t

JDN 2456160 EDT 13:55.

The Republican Party is scrambling to find viable Presidential candidates for next year’s election. The Democrats only have two major contenders: Hillary Clinton looks like the front-runner (and will obviously have the most funding), but Bernie Sanders is doing surprisingly well, and is particularly refreshing because he is running purely on his principles and ideas. He has no significant connections, no family dynasty (unlike Jeb Bush and, again, Hillary Clinton) and not a huge amount of wealth (Bernie’s net wealth is about $500,000, making him comfortably upper-middle class; compare to Hillary’s $21.5 million and her husband’s $80 million); but he has ideas that resonate with people. Bernie Sanders is what politics is supposed to be. Clinton’s campaign will certainly raise more than his; but he has already raised over $4 million, and if he makes it to about $10 million studies suggest that additional spending above that point is largely negligible. He actually has a decent chance of winning, and if he did it would be a very good sign for the future of America.

But the Republican field is a good deal more contentious, and the 19 candidates currently running have been scrambling to prove that they are the most right-wing in order to impress far-right primary voters. (When the general election comes around, whoever wins will of course pivot back toward the center, changing from, say, outright fascism to something more like reactionism or neo-feudalism. If you were hoping they’d pivot so far back as to actually be sensible center-right capitalists, think again; Hillary Clinton is the only one who will take that role, and they’ll go out of their way to disagree with her in every way they possibly can, much as they’ve done with Obama.) One of the ways that Republicans are hoping to prove their right-wing credentials is by proposing a flat income tax and eliminating the IRS.

Unlike most of their proposals, I can see why many people think this actually sounds like a good idea. It would certainly dramatically reduce bureaucracy, and that’s obviously worthwhile since excess bureaucracy is pure deadweight loss. (A surprising number of economists seem to forget that government does other things besides create excess bureaucracy, but I must admit it does in fact create excess bureaucracy.)

Though if they actually made the flat tax rate 20% or even—I can’t believe this is seriously being proposed—10%, there is no way the federal government would have enough revenue. The only options would be (1) massive increases in national debt (2) total collapse of government services—including their beloved military, mind you, or (3) directly linking the Federal Reserve quantitative easing program to fiscal policy and funding the deficit with printed money. Of these, 3 might not actually be that bad (it would probably trigger some inflation, but actually we could use that right now), but it’s extremely unlikely to happen, particularly under Republicans. In reality, after getting a taste of 2, we’d clearly end up with 1. And then they’d be complaining about the debt and clamor for more spending cuts, more spending cuts, ever more spending cuts, but there would simply be no way to run a functioning government on 10% of GDP in anything like our current system. Maybe you could do it on 20%—maybe—but we currently spend more like 35%, and that’s already a very low amount of spending for a First World country. The UK is more typical at 47%, while Germany is a bit low at 44%; Sweden spends 52% and France spends a whopping 57%. Anyone who suggests we cut government spending from 35% to 20% needs to explain which 3/7 of government services are going to immediately disappear—not to mention which 3/7 of government employees are going to be immediately laid off.

And then they want to add investment deductions; in general investment deductions are a good thing, as long as you tie them to actual investments in genuinely useful things like factories and computer servers. (Or better yet, schools, research labs, or maglev lines, but private companies almost never invest in that sort of thing, so the deduction wouldn’t apply.) The kernel of truth in the otherwise ridiculous argument that we should never tax capital is that taxing real investment would definitely be harmful in the long run. As I discussed with Miles Kimball (a cognitive economist at Michigan and fellow econ-blogger I hope to work with at some point), we could minimize the distortionary effects of corporate taxes by establishing a strong deduction for real investment, and this would allow us to redistribute some of this enormous wealth inequality without dramatically harming economic growth.

But if you deduct things that aren’t actually investments—like stock speculation and derivatives arbitrage—then you reduce your revenue dramatically and don’t actually incentivize genuinely useful investments. This is the problem with our current system, in which GE can pay no corporate income tax on $108 billion in annual profit—and you know they weren’t using all that for genuinely productive investment activities. But then, if you create a strong enforcement system for ensuring it is real investment, you need bureaucracy—which is exactly what the flat tax was claimed to remove. At the very least, the idea of eliminating the IRS remains ridiculous if you have any significant deductions.

Thus, the benefits of a flat income tax are minimal if not outright illusory; and the costs, oh, the costs are horrible. In order to have remotely reasonable amounts of revenue, you’d need to dramatically raise taxes on the majority of people, while significantly lowering them on the rich. You would create a direct transfer of wealth from the poor to the rich, increasing our already enormous income inequality and driving millions of people into poverty.

Thus, it would be difficult to more clearly demonstrate that you care only about the interests of the top 1% than to propose a flat income tax. I guess Mitt Romney’s 47% rant actually takes the cake on that one though (Yes, all those freeloading… soldiers… and children… and old people?).

Many Republicans are insisting that a flat tax would create a surge of economic growth, but that’s simply not how macroeconomics works. If you steeply raise taxes on the majority of people while cutting them on the rich, you’ll see consumer spending plummet and the entire economy will be driven into recession. Rich people simply don’t spend their money in the same way as the rest of us, and the functioning of the economy depends upon a continuous flow of spending. There is a standard neoclassical economic argument about how reducing spending and increasing saving would lead to increased investment and greater prosperity—but that model basically assumes that we have a fixed amount of stuff we’re either using up or making more stuff with, which is simply not how money works; as James Kroeger cogently explains on his blog “Nontrivial Pursuits”, money is created as it is needed; investment isn’t determined by people saving what they don’t spend. Indeed, increased consumption generally leads to increased investment, because our economy is currently limited by demand, not supply. We could build a lot more stuff, if only people could afford to buy it.

And that’s not even considering the labor incentives; as I already talked about in my previous post on progressive taxation, there are two incentives involved when you increase someone’s hourly wage. On the one hand, they get paid more for each hour, which is a reason to work; that’s the substitution effect. But on the other hand, they have more money in general, which is a reason they don’t need to work; that’s the income effect. Broadly speaking, the substitution effect dominates at low incomes (about $20,000 or less), the income effect dominates at high incomes (about $100,000 or more), and the two effects cancel out at moderate incomes. Since a tax on your income hits you in much the same way as a reduction in your wage, this means that raising taxes on the poor makes them work less, while raising taxes on the rich makes them work more. But if you go from our currently slightly-progressive system to a flat system, you raise taxes on the poor and cut them on the rich, which would mean that the poor would work less, and the rich would also work less! This would reduce economic output even further. If you want to maximize the incentive to work, you want progressive taxes, not flat taxes.

Flat taxes sound appealing because they are so simple; even the basic formula for our current tax rates is complicated, and we combine it with hundreds of pages of deductions and credits—not to mention tens of thousands of pages of case law!—making it a huge morass of bureaucracy that barely anyone really understands and corporate lawyers can easily exploit. I’m all in favor of getting rid of that; but you don’t need a flat tax to do that. You can fit the formula for a progressive tax on a single page—indeed, on a single line: r = 1 – I^-p

That’s it. It’s simple enough to be plugged into any calculator that is capable of exponents, not to mention efficiently implemented in Microsoft Excel (more efficiently than our current system in fact).

Combined with that simple formula, you could list all of the sensible deductions on a couple of additional pages (business investments and educational expenses, mostly—poverty should be addressed by a basic income, not by tax deductions on things like heating and housing, which are actually indirect corporate subsidies), along with a land tax (one line: $3000 per hectare), a basic income (one more line: $8,000 per adult and $4,000 per child), and some additional excise taxes on goods with negative externalities (like alcohol, tobacco, oil, coal, and lead), with a line for each; then you can provide a supplementary manual of maybe 50 pages explaining the detailed rules for applying each of those deductions in unusual cases. The entire tax code should be readable by an ordinary person in a single sitting no longer than a few hours. That means no more than 100 pages and no more than a 7th-grade reading level.

Why do I say this? Isn’t that a ridiculous standard? No, it is a Constitutional imperative. It is a fundamental violation of your liberty to tax you according to rules you cannot reasonably understand—indeed, bordering on Kafkaesque. While this isn’t taxation without representation—we do vote for representatives, after all—it is something very much like it; what good is the ability to change rules if you don’t even understand the rules in the first place? Nor would it be all that difficult: You first deduct these things from your income, then plug the result into this formula.

So yes, I absolutely agree with the basic principle of tax reform. The tax code should be scrapped and recreated from scratch, and the final product should be a primary form of only a few pages combined with a supplementary manual of no more than 100 pages. But you don’t need a flat tax to do that, and indeed for many other reasons a flat tax is a terrible idea, particularly if the suggested rate is 10% or 15%, less than half what we actually spend. The real question is why so many Republican candidates think that this will appeal to their voter base—and why they could actually be right about that.

Part of it is the entirely justified outrage at the complexity of our current tax system, and the appealing simplicity of a flat tax. Part of it is the long history of American hatred of taxes; we were founded upon resisting taxes, and we’ve been resisting taxes ever since. In some ways this is healthy; taxes per se are not a good thing, they are a bad thing, a necessary evil.

But those two things alone cannot explain why anyone would advocate raising taxes on the poorest half of the population while dramatically cutting them on the top 1%. If you are opposed to taxes in general, you’d cut them on everyone; and if you recognize the necessity of taxation, you’d be trying to find ways to minimize the harm while ensuring sufficient tax revenue, which in general means progressive taxation.

To understand why they would be pushing so hard for flat taxes, I think we need to say that many Republicans, particularly those in positions of power, honestly do think that rich people are better than poor people and we should always give more to the rich and less to the poor. (Maybe it’s partly halo effect, in which good begets good and bad begets bad? Or maybe just world theory, the ingrained belief that the world is as it ought to be?)

Romney’s 47% rant wasn’t an exception; it was what he honestly believes, what he says when he doesn’t know he’s on camera. He thinks that he earned every penny of his $250 million net wealth; yes, even the part he got from marrying his wife and the part he got from abusing tax laws, arbitraging assets and liquidating companies. He thinks that people who live on $4,000 or even $400 a year are simply lazy freeloaders, who could easily work harder, perhaps do some arbitrage and liquidation of their own (check out these alleged “rags to riches” stories including the line “tried his hand at mortgage brokering”), but choose not to, and as a result deserve what they get. (It’s important to realize just how bizarre this moral attitude truly is; even if I thought you were the laziest person on Earth, I wouldn’t let you starve to death.) He thinks that the social welfare programs which have reduced poverty but never managed to eliminate it are too generous—if he even thinks they should exist at all. And in thinking these things, he is not some bizarre aberration; he is representing an entire class of people, nearly all of whom vote Republican.

The good news is, these people are still in the minority. They hold significant sway over the Republican primary, but will not have nearly as much impact in the general election. And right now, the Republican candidates are so numerous and so awful that I have trouble seeing how the Democrats could possibly lose. (But please, don’t take that as a challenge, you guys.)

The moral—and economic—case for progressive taxation

JDN 2456935 PDT 09:44.

Broadly speaking, there are three ways a tax system can be arranged: It can be flat, in which every person pays the same tax rate; it can be regressive, in which people with higher incomes pay lower rates; or it can be progressive, in which case people with higher incomes pay higher rates.

There are certain benefits to a flat tax: Above all, it’s extremely easy to calculate. It’s easy to determine how much revenue a given tax rate will raise; multiply the rate times your GDP. It’s also easy to determine how much a given person should owe; multiply the rate times their income. This also makes the tax withholding process much easier; a fixed proportion can be withheld from all income everyone makes without worrying about how much they made before or are expected to make later. If your goal is minimal bureaucracy, a flat tax does have something to be said for it.

A regressive tax, on the other hand, is just as complicated as a progressive tax but has none of the benefits. It’s unfair because you’re actually taking more from people who can afford the least. (Note that this is true even if the rich actually pay a higher total; the key point, which I will explain in detail shortly, is that a dollar is worth more to you if you don’t have very many.) There is basically no reason you would ever want to have a regressive tax system—and yet, all US states have regressive tax systems. This is mainly because they rely upon sales taxes, which are regressive because rich people spend a smaller portion of what they have. If you make $10,000 per year, you probably spend $9,500 (you may even spend $15,000 and rack up the difference in debt!). If you make $50,000, you probably spend $40,000. But if you make $10 million, you probably only spend $4 million. Since sales taxes only tax on what you spend, the rich effectively pay a lower rate. This could be corrected to some extent by raising the sales tax on luxury goods—say a 20% rate on wine and a 50% rate on yachts—but this is awkward and very few states even try. Not even my beloved California; they fear drawing the ire of wineries and Silicon Valley.

The best option is to make the tax system progressive. Thomas Piketty has been called a “Communist” for favoring strongly progressive taxation, but in fact most Americans—including Republicans—agree that our tax system should be progressive. (Most Americans also favor cutting the Department of Defense rather than Medicare. This then raises the question: Why isn’t Congress doing that? Why aren’t people voting in representatives to Congress who will do that?) Most people judge whether taxes are fair based on what they themselves pay—which is why, in surveys, the marginal rate on the top 1% is basically unrelated to whether people think taxes are too high, even though that one bracket is the critical decision in deciding any tax system—you can raise about 20% of your revenue by hurting about 1% of your people. In a typical sample of 1,000 respondents, only about 10 are in the top 1%. If you want to run for Congress, the implication is clear: Cut taxes on all but the top 1%, raise them enormously on the top 0.1%, 0.01%, and 0.001%, and leave the 1% the same. People will feel that you’ve made the taxes more fair, and you’ve also raised more revenue. In other words, make the tax system more progressive.

The good news on this front is that the US federal tax system is progressive—barely. Actually the US tax system is especially progressive over the whole distribution—by some measures the most progressive in the world—but the problem is that it’s not nearly progressive enough at the very top, where the real money is. The usual measure based on our Gini coefficient ignores the fact that Warren Buffett pays a lower rate than his secretary. The Gini is based on population, and billionaires are a tiny portion of the population—but they are not a tiny portion of the money. Net wealth of the 400 richest people (the top 0.0001%) adds up to about $2 trillion (13% of our $15 trillion GDP, or about 4% of our $54 trillion net wealth). It also matters of course how you spend your tax revenue; even though Sweden’s tax system is no more progressive than ours and their pre-tax inequality is about the same, their spending is much more targeted at reducing inequality.

Progressive taxation is inherently more fair, because the value of a dollar decreases the more you have. We call this diminishing marginal utility of wealth. There is a debate within the cognitive economics literature about just how quickly the marginal utility of wealth decreases. On the low end, Easterlin argues that it drops off extremely fast, becoming almost negligible as low as $75,000 per year. This paper is on the high end, arguing that marginal utility decreases “only” as the logarithm of how much you have. That’s what I’ll use in this post, because it’s the most conservative reasonable estimate. I actually think the truth is somewhere in between, with marginal utility decreasing about exponentially.

Logarithms are also really easy to work with, once you get used to them. So let’s say that the amount of happiness (utility) U you get from an amount of income I is like this: U = ln(I)

Now let’s suppose the IRS comes along and taxes your money at a rate r. We must have r < 1, or otherwise they’re trying to take money you don’t have. We don’t need to have r > 0; r < 0 would just mean that you receive more in transfers than you lose in taxes. For the poor we should have r < 0.

Now your happiness is U = ln((1-r)I).

By the magic of logarithms, this is U = ln(I) + ln(1-r).

If r is between 0 and 1, ln(1-r) is negative and you’re losing happiness. (If r < 0, you’re gaining happiness.) The amount of happiness you lose, ln(1-r), is independent of your income. So if your goal is to take a fixed amount of happiness, you should tax at a fixed rate of income—a flat tax.

But that really isn’t fair, is it? If I’m getting 100 utilons of happiness from my money and you’re only getting 2 utilons from your money, then taking that 1 utilon, while it hurts the same—that’s the whole point of utility—leaves you an awful lot worse off than I. It actually makes the ratio between us worse, going from 50 to 1, all the way up to 99 to 1.

Notice how if we had a regressive tax, it would be obviously unfair—we’d actually take more utility from poor people than rich people. I have 100 utilons, you have 2 utilons; the taxes take 1.5 of yours but only 0.5 of mine. That seems frankly outrageous; but it’s what all US states have.

Most of the money you have is ultimately dependent on your society. Let’s say you own a business and made your wealth selling products; it seems like you deserve to have that wealth, doesn’t it? (Don’t get me started on people who inherited their wealth!) Well, in order to do that, you need to have strong institutions of civil government; you need security against invasion; you need protection of property rights and control of crime; you need a customer base who can afford your products (that’s our problem in the Second Depression); you need workers who are healthy and skilled; you need a financial system that provides reliable credit (also a problem). I’m having trouble finding any good research on exactly what proportion of individual wealth is dependent upon the surrounding society, but let’s just say Bill Gates wouldn’t be spending billions fighting malaria in villages in Ghana if he had been born in a village in Ghana. It doesn’t matter how brilliant or determined or hard-working you are, if you live in a society that can’t support economic activity.

In other words, society is giving you a lot of happiness you wouldn’t otherwise have. Because of this, it makes sense that in order to pay for all that stuff society is doing for you (and maintain a stable monetary system), they would tax you according to how much happiness they’re giving you. Hence we shouldn’t tax your money at a constant rate; we should tax your utility at a constant rate and then convert back to money. This defines a new sort of “tax rate” which I’ll call p. Like our tax rate r, p needs to be less than 1, but it doesn’t need to be greater than 0.

Of the U = ln(I) utility you get from your money, you will get to keep U = (1-p) ln(I). Say it’s 10%; then if I have 100 utilons, they take 10 utilons and leave me with 90. If you have 2 utilons, they take 0.2 and leave you with 1.8. The ratio between us remains the same: 50 to 1.

What does this mean for the actual tax rate? It has to be progressive. Very progressive, as a matter of fact. And in particular, progressive all the way up—there is no maximum tax bracket.

The amount of money you had before is just I.

The amount of money you have now can be found as the amount of money I’ that gives you the right amount of utility. U = ln(I’) = (1-p) ln(I). Take the exponential of both sides: I’ = I^(1-p).

The units on this are a bit weird, “dollars to the 0.8 power”? Oddly, this rarely seems to bother economists when they use Cobb-Douglas functions which are like K^(1/3) L^(2/3). It bothers me though; to really make this tax system in practice you’d need to fix the units of measurement, probably using some subsistence level. Say that’s set at $10,000; instead of saying you make $2 million, we’d say you make 200 subsistence levels.

The tax rate you pay is then r = 1 – I’/I, which is r = 1 – I^-p. As I increases, I^-p decreases, so r gets closer and closer to 1. It never actually hits 1 (that would be a 100% tax rate, which hardly anyone thinks is fair), but for very large income is does get quite close.

Here, let’s use some actual numbers. Suppose as I said we make the subsistence level $10,000. Let’s also set p = 0.1, meaning we tax 10% of your utility. Then, if you make the US median individual income, that’s about $30,000 which would be I = 3. US per-capita GDP of $55,000 would be I = 5.5, and so on. I’ll ignore incomes below the subsistence level for now—basically what you want to do there is establish a basic income so that nobody is below the subsistence level.

I made a table of tax rates and after-tax incomes that would result:

Pre-tax income Tax rate After-tax income
$10,000 0.0% $10,000
$20,000 6.7% $18,661
$30,000 10.4% $26,879
$40,000 12.9% $34,822
$50,000 14.9% $42,567
$60,000 16.4% $50,158
$70,000 17.7% $57,622
$80,000 18.8% $64,980
$90,000 19.7% $72,247
$100,000 20.6% $79,433
$1,000,000 36.9% $630,957
$10,000,000 49.9% $5,011,872
$100,000,000 60.2% $39,810,717
$1,000,000,000 68.4% $316,227,766

What if that’s not enough revenue? We could raise to p = 0.2:

Pre-tax income Tax rate After-tax income
$10,000 0.0% $10,000
$20,000 12.9% $17,411
$30,000 19.7% $24,082
$40,000 24.2% $30,314
$50,000 27.5% $36,239
$60,000 30.1% $41,930
$70,000 32.2% $47,433
$80,000 34.0% $52,780
$90,000 35.6% $57,995
$100,000 36.9% $63,096
$1,000,000 60.2% $398,107
$10,000,000 74.9% $2,511,886
$100,000,000 84.2% $15,848,932
$1,000,000,000 90.0% $100,000,000

The richest 400 people in the US have a combined net wealth of about $2.2 trillion. If we assume that billionaires make about a 10% return on their net wealth, this 90% rate would raise over $200 billion just from those 400 billionaires alone, enough to pay all interest on the national debt. Let me say that again: This tax system would raise enough money from a group of people who could fit in a large lecture hall to provide for servicing the national debt. And it could do so indefinitely, because we are only taxing the interest, not the principal.

And what if that’s still not enough? We could raise it even further, to p = 0.3. Now the tax rates look a bit high for most people, but not absurdly so—and notice how the person at the poverty line is still paying nothing, as it should be. The millionaire is unhappy with 75%, but the billionaire is really unhappy with his 97% rate. But the government now has plenty of money.

Pre-tax income Tax rate After-tax income
$10,000 0.0% $10,000
$20,000 18.8% $16,245
$30,000 28.1% $21,577
$40,000 34.0% $26,390
$50,000 38.3% $30,852
$60,000 41.6% $35,051
$70,000 44.2% $39,045
$80,000 46.4% $42,871
$90,000 48.3% $46,555
$100,000 49.9% $50,119
$1,000,000 74.9% $251,189
$10,000,000 87.4% $1,258,925
$100,000,000 93.7% $6,309,573
$1,000,000,000 96.8% $31,622,777

Is it fair to tax the super-rich at such extreme rates? Well, why wouldn’t it be? They are living fabulously well, and most of their opportunity to do so is dependent upon living in our society. It’s actually not at all unreasonable to think that over 97% of the wealth a billionaire has is dependent upon society in this way—indeed, I think it’s unreasonable to imagine that it’s any less than 99.9%. If you say that the portion a billionaire receives from society is less than 99.9%, you are claiming that it is possible to become a millionaire while living on a desert island. (Remember, 0.1% of $1 billion is $1 million.) Forget the money system; do you really think that anything remotely like a millionaire standard of living is possible from catching your own fish and cutting down your own trees?Another fun fact is that this tax system will not change the ordering of income at all. If you were the 37,824th richest person yesterday, you will be the 37,824th richest person today; you’ll just have a lot less money while you do so. And if you were the 300,120,916th richest person, you’ll still be the 300,120,916th person, and probably still have the same amount of money you did before (or even more, if the basic income is doled out on tax day).

And these figures, remember, are based on a conservative estimate of how quickly the marginal utility of wealth decreases. I’m actually pretty well convinced that it’s much faster than that, in which case even these tax rates may not be progressive enough.

Many economists worry that taxes reduce the incentive to work. If you are taxed at 30%, that’s like having a wage that’s 30% lower. It’s not hard to imagine why someone might not work as much if they were being paid 30% less.

But there are actually two effects here. One is the substitution effect: a higher wage gives you more reason to work. The other is the income effect: having more money means that you can meet your needs without working as much.

For low incomes, the substitution effect dominates; if your pay rises from $12,000 a year to $15,000, you’re probably going to work more, because you get paid more to work and you’re still hardly wealthy enough to rest on your laurels.

For moderate incomes, the effects actually balance quite well; people who make $40,000 work about the same number of hours as people who make $50,000.

For high incomes, the income effect dominates; if your pay rises from $300,000 to $400,000, you’re probably going to work less, because you can pay all your bills while putting in less work.

So if you want to maximize work incentives, what should you do? You want to raise the wages of poor people and lower the wages of rich people. In other words, you want very low—or negative—taxes on the lower brackets, and very high taxes on the upper brackets. If you’re genuinely worried about taxes distorting incentives to work, you should be absolutely in favor of progressive taxation.

In conclusion: Because money is worth less to you the more of it you have, in order to take a fixed proportion of the happiness, we should be taking an increasing proportion of the money. In order to be fair in terms of real utility, taxes should be progressive. And this would actually increase work incentives.