A Canadian payroll dependency chart

Here is a somewhat similar graph for the IRS I scraped together a few years ago:

https://nampas.github.io/tax-map/

There are a lot of lines :D

Yeah, in the US it's a certain percentage up to a limit, and some people are exempt. Pretty simple in terms of doing payroll

All the complexity is when you file your actual return, and that one would literally be impossible to chart out because there are so many different nooks and crannies that exist that most people don't need to worry about but might so they are out there. I suspect that is also the case in Canada in addition to this payroll calculation nightmare

This demonstrates how any algorithm, software or not, works: Start with something desirable or necessary and add complications until you end up with a mess that can be used to yield arbitrary results, drive outsiders into madness, and summon some lesser demons if read in a chanting manner.

Now what could be done about this? The obvious answer is refactoring. That's what politicians promise in election campaigns and junior software developers demand when encountering a new code base. It's rarely ever done in practice because no one can disambiguate unnecessary from desired features and complexities. The second answer would be a clean implementation in some more formal framework (a statically typed language, a theorem prover, ...). That second solution often fails when attempted because the system is already unsound. Fortunately, no one cares about those "weird corner cases" and everything is left as-is until someone runs away with a million dollars or so.

Being someone who has some experience with tax law, the cycle of tax complexity goes like this:

1. Tax law is passed.

2. Really smart CPAs and Tax Lawyers figure out ways to legally avoid paying taxes.

3. Tax people issue regulations intended to close those loopholes.

4. Administrations change and they want to win votes and tweak the economy so they lower some taxes and add tax breaks.

5. New administration comes in and selectively reverses previous administration's program because of politics.

6. If the tax is international tax, then add really smart tax lawyer doing multi-jurisdictional tricks to lower taxes (e.g Double Irish With a Dutch Sandwich[1]) , governments trying to encourage multi-nationals to do business there by adding incentives to their tax code, the OECD coming in and trying to standardize tax stuff across jurisdictions to prevent this, individual pairs of countries doing tax treaties with each other, etc.

[1] https://www.investopedia.com/terms/d/double-irish-with-a-dut...

thats pretty cool, I wonder though what the implication is if there is a bug or package hijacking? Are you expected to cross check the calculations and they are only offered as a convenience, and not authoritative?