Raising taxes will not raise tax revenues

Karl Denninger buried a very important stat in a post about Germany here:

http://market-ticker.org/archives/2347-I-Know!-Lets-Vilify-Germany!.html

Here is the stat:

Historically, no matter the tax rate, governments seem to be unable to collect more than about 20% of GDP in taxes.

The human nature in people seem to have a built in monitor for what is fair in paying taxes. Once that threshold is reached people will start to find ways to avoid the increase in taxes such as saving more instead of spending, using cash transactions, bartering, paying people in perks, finding other ways to hide income/assets, starting businesses so that they can write off expenses and losses, move to other cities/states/countries that have lower tax rates , selling investments at a loss, setting up trusts, donating to charity, etc. Also, increased taxes will hurt GDP on the other side of the ratio.

We are going to see countless articles about "unexpected" shortfalls in tax revenues for cities, states, and countries over the next few years. Rasing tax rates DOES NOT mean that there will be a equal increase in tax revenues. Unfortunately, politicians are ignorant of math and the human nature in regard to paying "fair" amounts of taxes. They are going to continue to increase taxes and fees on everything they can think of but will, over and over, be shocked at how the tax revenue streams just aren't increasing accordingly. The MSM will be equally shocked.