In the tradition of "keeping the federal government out of our business," a dubious phrase in most instances, every State has the right to impose (or not, as it sees fit) a state sales tax. This varies from state to state, and some states have none at all, preferring to draw needed revenue from other sources (and, not incidentally, shoppers from neighboring states that do have sales taxes, e.g. NH vs. MA). Some states prefer to have a state sales tax but not a state income tax (e.g. Texas).
But at the end of the day, it is the states, and not the federal government, who decide how high their state sales taxes are, and, importantly, what is subject to the tax, and what is not. This is not the case in the European countries.
The administration of a VAT is a vast, cumbersome bureaucracy in itself, with a vast enforcement apparatus necessary, and huge opportunities for fraud and corruption. Most European countries started out with a 10% national VAT. It keeps creeping upward, never downward, and has only been eliminated on items that were forced abroad or underground when imposed. Dealers in gold and gold coins, for example, who usually operate on a margin of between 1% and 5%, can't survive if they have to charge 19% tax on top of their sales. Business would simply migrate to a nearby country with no VAT on such items (i.e. Luxembourg or Switzerland). Indeed, exactly that happened a few decades ago, and the VAT imposing countries (Germany, NL, Austria, e.g.) quickly realized they were being stupid, losing both taxpaying businesses, jobs, and revenue, so they eliminated it again.
VAT is now mostly between 19% (Germany, for example) and 25% (Denmark, for example). It hits hardest, of course, those low-income people who can least afford it. In Germany, it is called Mehrwertsteuer, pretty much a literal translation of "value added tax." Many Germans refer to it cynically as "Märchensteuer" which translates out to "Fairy Tale Tax" since they see its benefits as fictitious.
As a side note--the German constitution forbids double taxation in Germany. It seems that some 90 years ago, a certain group here was unfairly disadvantaged by special taxes imposed upon them and not on others, and the post-war Germans wanted to make sure that their new nation would forever forbid that. When a wealth tax was proposed by the left (and labeled a "jealousy tax" by the right), their Supreme Court struck it down as a double taxation. However, as a revenue raising measure, the government imposed VAT at the gas pump. Not just on the gasoline, but also on the gasoline tax that constituted the greater part of the price paid by the consumer. Germans now pay VAT on another tax, therefore, a double taxation--clearly in violation of their own constitution. As fate would have it, a neighbor of ours here in Germany is a retired judge on the tax court. He is also a professor of tax law at the University of Bonn, and wrote his doctoral thesis on double taxation. I asked him if the tax-on-tax at the gas pump wasn't unconstitutional under German law? He said, "absolutely!" I asked why it was still standing? He asked me if I had a spare half million Euros to organize and mount the necessary class-action suit to bring it before the courts. I checked. I didn't. He said, neither did anyone else. He said that if it had come before him as a judge, he would have struck it down immediately. But it never did, and if it means an extra €13.28 twice a month out of your gas budget, are you going to go to court over it?
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