blog

git clone https://git.ce9e.org/blog.git

commit
e0c381f950f282144c8b7537211a0b15ee3b38e5
parent
1f225ed7e2be6dcf23664e00a0336112ac8daf7b
Author
Tobias Bengfort <tobias.bengfort@posteo.de>
Date
2025-05-21 05:35
use latexmath pandoc feature

Diffstat

M Makefile 2 +-
M _content/posts/2025-05-16-tax-curves/index.md 75 ++++++++++---------------------------------------------------

2 files changed, 13 insertions, 64 deletions


diff --git a/Makefile b/Makefile

@@ -4,7 +4,7 @@ PAGES_MD := $(shell find _content -name 'index.md' | sed 's/^_content/build/')
    4     4 PAGES_FEED := $(shell find _content -name 'index.md' | sed 's/md$$/html/')
    5     5 STATIC := $(shell find static -type f | sed 's/^/build\//')
    6     6 IMG := $(shell find _content -regex '.*\.\(png\|gif\|jpg\)$$' | sed 's/^_content/build/')
    7    -1 PANDOC_ARGS = -f markdown-smart --wrap=none --lua-filter filters/*.lua
   -1     7 PANDOC_ARGS = -f markdown-smart --mathml --wrap=none --lua-filter filters/*.lua
    8     8 
    9     9 .PHONY: all
   10    10 all: $(IMG) build/index.html build/projects/index.html $(PAGES) $(PAGES_MD) build/feed.xml build/feed-archive.xml build/feed.json build/feed-archive.json $(STATIC) build/static/style.css

diff --git a/_content/posts/2025-05-16-tax-curves/index.md b/_content/posts/2025-05-16-tax-curves/index.md

@@ -12,30 +12,21 @@ options for tax curves, without any claim to real-world merit.
   12    12 
   13    13 ## Basics
   14    14 
   15    -1 We will look at functions where <math><mi>x</mi></math> is the income before
   16    -1 taxes and <math><mi>f</mi><mo>(</mo><mi>x</mi><mo>)</mo></math> is the
   17    -1 income after taxes.
   -1    15 We will look at functions where $x$ is the income before taxes and $f(x)$ is
   -1    16 the income after taxes.
   18    17 
   19    18 I am a big fan of folding some form of social security into the tax system, so
   20    -1 <math><mi>b</mi></math> will be the level of basic income everyone should have.
   -1    19 $f(0) = b$ will be the level of basic income everyone should have.
   21    20 
   22    -1 All functions will have a single additional parameter <math><mi>a</mi></math>
   23    -1 that can be used to adjust the system to the current economic situation,
   24    -1 basically raising or lowering taxes.
   -1    21 All functions will have a single additional parameter $a$ that can be used to
   -1    22 adjust the system to the current economic situation, basically raising or
   -1    23 lowering taxes.
   25    24 
   26    25 ## Linear
   27    26 
   28    27 The simplest model is a flat tax rate with basic income:
   29    28 
   30    -1 <math>
   31    -1     <mi>𝑓</mi><mo>(</mo><mi>𝑥</mi><mo>)</mo>
   32    -1     <mo>=</mo>
   33    -1     <mi>𝑎</mi>
   34    -1     <mo>&InvisibleTimes;</mo>
   35    -1     <mi>𝑥</mi>
   36    -1     <mo>+</mo>
   37    -1     <mi>𝑏</mi>
   38    -1 </math>
   -1    29 $f(x) = ax+b$
   39    30 
   40    31 ![](./linear.png)
   41    32 
@@ -49,25 +40,7 @@ Most real-world economies have progressive tax rates. That means: the higher
   49    40 your income, the higher your marginal tax rate. The classic mathematical
   50    41 function that grows to infinity but slows down while doing so is the logarithm:
   51    42 
   52    -1 <math>
   53    -1     <mi>𝑓</mi><mo>(</mo><mi>𝑥</mi><mo>)</mo>
   54    -1     <mo>=</mo>
   55    -1     <mi>𝑎</mi>
   56    -1     <mo>&InvisibleTimes;</mo>
   57    -1     <mi>ln</mi>
   58    -1     <mo>(</mo>
   59    -1     <mrow>
   60    -1         <mfrac>
   61    -1             <mi>x</mi>
   62    -1             <mi>a</mi>
   63    -1         </mfrac>
   64    -1         <mo>+</mo>
   65    -1         <mn>1</mn>
   66    -1     </mrow>
   67    -1     <mo>)</mo>
   68    -1     <mo>+</mo>
   69    -1     <mi>𝑏</mi>
   70    -1 </math>
   -1    43 $f(x) = a \ln(\frac{x}{a} + 1) + b$
   71    44 
   72    45 ![](log.png)
   73    46 
@@ -88,31 +61,7 @@ money than everyone else.
   88    61 Another type of functions that go up to infinity but slow down on the way are
   89    62 power functions like this one:
   90    63 
   91    -1 <math>
   92    -1     <mi>𝑓</mi><mo>(</mo><mi>𝑥</mi><mo>)</mo>
   93    -1     <mo>=</mo>
   94    -1     <msup>
   95    -1         <mrow>
   96    -1             <mo>(</mo>
   97    -1             <mrow>
   98    -1                 <mfrac>
   99    -1                     <mi>x</mi>
  100    -1                     <mrow>
  101    -1                         <mi>a</mi>
  102    -1                         <mo>&InvisibleTimes;</mo>
  103    -1                         <mi>b</mi>
  104    -1                     <mrow>
  105    -1                 </mfrac>
  106    -1                 <mo>+</mo>
  107    -1                 <mn>1</mn>
  108    -1             </mrow>
  109    -1             <mo>)</mo>
  110    -1         </mrow>
  111    -1         <mi>a</mi>
  112    -1     </msup>
  113    -1     <mo>&InvisibleTimes;</mo>
  114    -1     <mi>𝑏</mi>
  115    -1 </math>
   -1    64 $f(x) = (\frac{x}{ab} + 1)^a b$
  116    65 
  117    66 ![](pow.png)
  118    67 
@@ -120,6 +69,6 @@ Like with the logarithm, the marginal tax rate starts at 0% and grows towards
  120    69 100%. However, it doesn't grow as quickly, which puts it somewhere in between
  121    70 the logarithmic and linear versions. So this feels the most balanced.
  122    71 
  123    -1 I also like that <math><mi>a</mi></math> has an intuitive interpretation (how
  124    -1 curved to curve is). So if I were ever going to be minister of finance, this
  125    -1 would probably be the version that my advisors would have to talk me out of.
   -1    72 I also like that $a$ has an intuitive interpretation (how curved the curve is).
   -1    73 So if I were ever going to be minister of finance, this would probably be the
   -1    74 version that my advisors would have to talk me out of.