This is true. No jurisdiction in the world has found a sales tax rate in the 10-15% range (non-tax-inclusive) sustainable due to evasion. The non-tax-inclusive rate of the so-called "Fair Tax" is, as you observed, 30%.
When sales tax rates get that high, sales taxes are converted to VATs. We've seen it in Canada, South America, Europe, Africa and most recently in India.
"We" have seen it nowhere since none of the countries you mention have a "sales tax" that was at all like the FairTax. NONE.
You're merely distributing disinformation. The "sales taxes" you mention were like the Indian transaction/transfer tax - see post #85 just above for more definitive information.
The has never - NEVER - been a definitive study by any recognized economist of any standing that supports your claim about sales tax rates above 10 - 15%. That is an outright falsehood you have manufactured unless you can post a link to such a study for us to examine.
Most of the EU countries you include were REQUIRED to convert to a VAT as a condition for joining the EU no matter what tax system they had before.
What do you think self employed people have to do now? If I get a commission check, I need to set aside at least 30% now to pay self employement and federal and state income taxes. The incentive to evade is already there. That is why many people (not including me of course) exaggerate expenses or try to take cash. It will be harder to evade the sales tax than under our current system. I spend most of my money on utilities, food and cars. Am I going to go to some back ally to buy eggs and milk? How about electricity and gas - from someone's trunk in a parking lot? With big retailers doing most of the business, collection of sales taxes from thousands will be easier than collecting income tax from millions.