Who pays the tax?
All this is a bit academic. It misses the point entirely, that it is the CUSTOMER that pays the tax, not the seller. If Amazon is dodging paying tax, their selling price reflects, at least, in part, that reduction. Everyone wants to pay less tax, and everyone wants that shortfall to be paid by someone else. Preferably by someone in another country. Governments are greedy for tax, and their record shows that spending that tax is seldom efficient. What we need is LESS tax and more sensible spending. Not that we're ever likely to see it.