Dr Bryce Wilkinson: Should New Zealanders aspire to be among the world’s most taxed people?

Max Rashbrooke's recent research note, "High earner tax rates: New Zealand in context," makes a case that rich people in New Zealand pay less tax than they would on the same income in some of the highest-taxed countries in the world.
But is this really the case? And if it is the case, what follows?

The case is problematic. It is based on a stylised OECD study that does not take into account issues of loopholes, realised versus unrealised gains, inflation-adjustments and IRD refunds for capital losses.