Re: Just change the current tax laws.
Re: "If you sell advertising/software/etc. in France, that revenue accrues to the French subsidiary, and can't be funneled to <somewhere else>"
I think you meant "that profit accrues" but that's the problem - you sell some software for 100 Euros in France and the French subsidiary internally pays it's Irish subsidiary 99.99 Euros because the company says the software IP is "owned" by the Irish subsidiary. Hence only 0.01 profit in France and low French taxes on this 0.01.
Fixing this in general requires honest intra-company pricing which is hard to enforce, although countries could prosecute some cases to encourage honesty.
On the other hand if you really meant "that revenue accrues to the French subsidiary" then this is what happens today, so companies can choose which country shows the profit (same as today) or this becomes the turnover tax.
Possibly the right answer is percentage profit tax, i.e. if 10% of a company's revenue is in France then they would page French tax on 10% of their global profit regardless of inter-company accounting. This may be difficult though assuming different countries have different rules on what counts as taxable profit.
On the other hand if there's really no R&D in France then there's less added value and presumably less tax justified.
Biting the hand that feeds IT
