> I'm not familiar with the situation of New Zealand with respect to Australia (its neighbours). But the problem in the EU, is that there are a few countries (Ireland and the Netherlands inside the Union, and Switzerland which is right next door and enjoys many advantages and no constraints) which charge way less tax than the "central" EU countries. So companies have a tendency to set up their HQs in those countries.

Speaking as an Irish person, this is definitely true and tax is a big reason for a lot of the multinationals we have here.

However, also note that the Irish people have one the highest debt per capita, basically incurred to pay off debts to EU/UK banks during the financial crisis. If you mutualise debt, and do the capital markets union then you could 100% fix this (but the political will definitely isn't there for that).

Ah, I did wonder how state level taxes were being accounted for, seems like the answer is they aren't. I guess I could have looked that up before posting. The values here[0] are markedly different. It shows Germany at 45%, France at 51.53%, US at 29.21% and Denmark at 50%. So I was way off the mark there, although I did think something seemed very off with those numbers. France is the 10th highest in the world, with many of the countries above it being tiny island countries or countries with vast oil reveres relative to their size like Norway and Kuwait. With this being the case, it does seem hard to imagine that more taxes will fix everything.

[0] Government revenue, percent of GDP - https://www.imf.org/external/datamapper/rev@FPP/

Also relevant: Government expenditure, percent of GDP - https://www.imf.org/external/datamapper/exp@FPP/