Sounds great, and I am sure you are an excellent doctor, but I wish you were a better economist when you are trying to contrast the two countries and try to determine cause and effect.
First and foremost, New Zealand has a better free market economy than the US. For all the blathering and pomposity about the free market in America, it actually scores quite low, and having a free market is one of the biggest determining factors in economic mobility and financial equity.
https://www.heritage.org/index/pages/all-country-scores
You will recognize many "better" countries on that list way above America.
And while there is race tension in NZ, I think it is way better than in America, where its not native Americans vs everyone else, its multiple ethnicities trying to clamor for position. In the USA, and most of the globe, there is no unity, homogeneity...no true concept of any "we". without that, it is very difficult to have a high trust society.
You compare the minimum wage, at 7.25 but less than half of the states in the US actually have that minimum.
And people who are under 133% of the federal poverty level are covered by medicaid. as they progress above the poverty level the amount of benefit drops.
I'm not saying this is great healthcare, or that there arent other complications, but to say that min wage workers don't have it, isn't true.
As for the 90% tax in the 50's, while that was true not he books, it's not functionally true. You are confusing top marginal tax rate with the effective top tax rate.
The drop in the income tax on the wealthy was in recognition that the wealthy don't pay taxes for the most part, however they do pay most of the taxes (60-70% of tax revenue comes from the wealthy). The goal was to increase revenue, by lowering taxes, which it did.
https://taxfoundation.org/data/all/federal/taxes-on-the-rich-1950s-not-high/
https://www.heritage.org/taxes/report/the-historical-lessons-lower-tax-rates
I agree with your contentions about wealth inequality. lower inequality breeds a better civilization. However forcing it into equality is when it goes wrong. People are crazy if they think well connected rich people are going to let the government take their money, they will simply put in rules that reduce competition, and favor the businesses they own in order to create more wealth. That's the American story, regulatory capture, rule by lobbyists.
I hope NZ keeps their eye on the free market ball. Thats the path that America left decades ago.
