Re: Ok but how much tax is fair?
No IP licensing, market value for intra-company goods (e.g., Starbucks coffee beans should be sold to Starbucks UK at market price for beans), and so on.
I think one's easier than the other. I also think there are tax rules that are meant to prevent contrivances used to avoid/evade taxes. There are also huge problems if tax authorities are allowed to decide market price, and that alreay happens when assessed values can be far higher than actual market value or cost. And of course it'll probably be used against small businesses rather than the FANGs with their legions of lawyers & accountants.
Contrivance though could work, so the Starbucks example. It'd be good business if a company used it's skill to lower the roasting & processing cost of coffee beans. It doesn't make sense though that Starbucks is probably the world's most expensive supplier.. Especially as there's really only one customer. ISTR Starbucks claimed an Italian company bought a few beans, but that seemed rather contrived. Regulators do have various tools to test shenangigans though, ie benchmarking, or notional 'equally efficient operator' tests that could be used more fairly.