Do You Hear The
People Sing
Do you hear
the people sing?
Singing the song of angry men?
It is the music of the people
Who will not be slaves again!
When the beating of your heart
Echoes the beating of the drums
There is a life about to start
When tomorrow comes
Fool me once shame
on me. Fool me twice shame on you.
In an ideal world, the income tax debate would go like
this. What is the lowest acceptable income tax rate. The Bible might call this a tithe,
10%. If that is the lowest rate, then according to the laws of normal distributions,
the mode/mean/median rate should be 20%, and the highest rate should be 40%.
The Tax Cut and Jobs Act, TCJA, sets the lowest tax rate at 10% and the highest
tax rate at 37%, which is not exactly normal, but is arguably close enough. It also
confuses marginal tax rates and effective tax rates, but that will be discussed later.
The question is how to transition from a rate of 10% to a rate
of 37% in a fair manner. One suggestion might be to pick an arbitrary amount
and transition at that income. However establishing that transition income would be contentious
politically, but mathematically it should be such that the median tax rate is paid by the median income. Since it is a tax on income, not a tax on individuals, if income is not normally
distributed among individuals, then arguably the transition should follow the distribution of
income not people. The distribution of income is not normal (a statistical term, not an ethical
term). If incomes were distributed normally, then the mean would be equal to
the median would be equal to the mode, the most common value. According to the
US Census for income, the mean is definitely not the median. One of the most
common non-normal distributions is the exponential distribution. Without debating
why incomes are not normally distributed, the transition from the lowest tax rate to
the highest tax rate should arguably follow this existing distribution of income.
(Interestingly, a flat tax also implies that everyone has the same income. To
be mathematically consistent, those that argue for a flat tax must also be also
communists who argue that every individual should have the same income.)
Any non-linear distribution can be approximated by a
series of straight lines of EQUAL intervals, which is how calculus works.
There are seven brackets in the TCJA. Assuming that the top bracket is the full
amount, and the first bracket is the lowest amount, then there are five brackets in
which to make the transition (e.g. the total tax paid in the highest income in
the sixth of seven brackets should have an effective rate of 37%, the highest
rate). The effective tax rate at any income x is 10% + 27%*(1-e-λx), where 1/λ is the mean income
according to the exponential distribution. This can be approximated by a series
of straight lines, tax brackets, as:
a=λ*10%= 10% λ
b=λ*(10% + (1-e-.2)) = 28.1% λ
c=λ*(10% + (1-e-.2) + (1- e-.4)) = 61.1% λ
d=λ*(10% + (1-e-.2) + (1-e-.4) + (1-e-.6)) = 106.2% λ
e=λ*(10% + (1-e-.2) + (1-e-.4) + (1-e-.6) + (1-e-.8)) = 161.3% λ
f= λ*(10% + (1-e-.2) + (1-e-.4) + (1-e-.6) + (1-e-.8) + (1-e-.1) ) = 224.5% λ
This means that
the tax brackets are a simple problem given the highest tax rate, 37%, the lowest
tax rate, 10%, and the number of brackets, in this case seven. The only variable
in the table above that needs to be specified is the mean income. This should be
computed for each tax filing using the tax status (e.g. Single, Married Filing Jointly,
Married Filing Separately, Head Of Household, etc.). As an example, the US Census
specifies the mean household income as $102,316 in 2021 according to Income
in the United States: 2021: Current Population Reports. With this amount, and the actual percentages substituted in place of the exponential equations, the table would be:
Bracket
|
Lower income
|
Upper Income
|
Fixed Tax
|
Marginal
Tax Rate
(on amount above lowest income in bracket)
|
Lowest Effective Tax
|
Highest Effective Tax
|
1
|
$0
|
$102,316
|
$0
|
10%
|
10%
|
10%
|
2
|
$102,316
|
$204,632
|
$10,232
|
18.13%
|
10%
|
14%
|
3
|
$204,632
|
$306,948
|
$28,751
|
32.97%
|
14%
|
20%
|
4
|
$306,948
|
$409,264
|
$62,515
|
45.12%
|
20%
|
27%
|
5
|
$409,264
|
$511,580
|
$108,660
|
55.07%
|
27%
|
32%
|
6
|
$511,580
|
$613,896
|
$165,036
|
63.21%
|
32%
|
37%
|
7
|
$613,896
|
No
Limit
|
$229,699
|
37%
|
37%
|
37%
|
The 2022
TCJA Tax rates for Married Filing Jointly or Qualifying Widow (Widower) are:
Bracket
|
Lower
income
|
Upper
Income
|
Fixed
Tax
|
Marginal Tax Rate
(on amount above lowest income in bracket)
|
Lowest
Effective Tax
|
Highest
Effective Tax
|
1
|
$0
|
$20,550
|
$0
|
10%
|
10%
|
10.0%
|
2
|
$20,550
|
$83,550
|
$2,055
|
12%
|
10%
|
11.5%
|
3
|
$83,550
|
$178,150
|
$9,615
|
22%
|
11.5%
|
17.1%
|
4
|
$178,150
|
$340,100
|
$2,055
|
24%
|
17.1%
|
20.4%
|
5
|
$340,100
|
$431,900
|
$9,615
|
32%
|
20.4%
|
22.8%
|
6
|
$431,900
|
$647,850
|
$2,055
|
35%
|
22.8%
|
26.9%
|
7
|
$647,850
|
No Limit
|
$9,615
|
37%
|
26.9%
|
35.7%*
|
*The highest effective tax
rate in the highest tax bracket is not reached until the income is infinite. This
is the effective tax rate at an income of $5,000,000.
As
can be seen for the TCJA tax brackets, the brackets are not equal AND the effective
tax rates are confused with the marginal tax rates. This second error is like confusing speed
and acceleration, since both are first and second derivatives. The combination of these two errors results
in a tax code that does not transition between the lowest rate and the highest rate
according to the distribution of income. As can be seen in the figure below,
this means the incomes below ~$300,000 are currently paying
effective tax rates that should be charged only at higher incomes. The basic errors
were made beginning with the “Reagan” Tax Cuts of 1981 and have resulted in an over
taxation of the poor and middle class and an under taxation of the rich for over 40 years. If
the intent were to transition from the lowest tax rate to a maximum tax rate according
to the distribution of income, a math professor would give these tax codes a failing
grade.