Ok, but your previous post said "even if you are very optimist and assume that he’ll get exactly as much as he expects in taxes", so I was operating under that optimistic assumption. Was Yang planning to exempt any part of the GDP from his VAT? Genuine question but I didn't think he was.

Speaking of which, I googled Germany's VAT and it seems there are quite a few exemptions ("food, books, hotel accommodation, cultural services and other goods and services") that only get VATed at 7%, which is much closer to the 6% they apparently collect in practice. But sure, they probably do fail to collect quite a bit of what they theoretically could.