@ GTM_3442 - I can speak about Canada as I grew up in Canada.

In short, the Cdn income tax system is extremely complex and I mean virtually all filers would most be unaware of any tax laws they've broken. Even accountants and lawyers have a tough time deciphering the act. My tax prof (back in the 90s) explained the excessive complication was simply due to lawyers and accountants fighting in court and the wording to plug up loop holes which resulted in the ITA being over 1 million words long.

Generally speaking, Canada has 3 types of income for taxation; (A) working income, interest income, royalties, & bonuses, (B) Dividend Income, & (C) Capital Gains. The latter attracts the lowest form of taxation. The calculation for CGT in Canada is very straight forward. You take the sale price minus the 'adjusted cost base' which is the sale price (or FMV) less expenses related. For eg. buying stocks on the share market you can deduct commissions or related expense. When a person dies, deemed disposition applies which means 'fair market value' is factored. In the case of stocks, they just take the day's trading price. For real estate, generally the CRA will accept any reputable valuation if the GV or RV is disputed by the tax filer. After you calculate the gain, THEN you take HALF of that gain and pocket it. The OTHER HALF is what goes towards 'taxable income'. The reason why you pocket half of the gain as tax free is due to factoring inflation (and also saves a lot of computing of inflation rates over the years).

The most remarkable advantage Cdn residents have in terms of taxation is their ability to structure their income for taxation. Generally the rich and wealthy have like 90% of their income in the form of capital gains (very similar to the US model of how much tax the very rich pay). But it's not all for the rich that benefit, the working class (middle class) have ways to forego taxation on their income through investments like Kiwi Saver (called RRSPs). Up to 18% of the person's income can be allocated to a pension fund similar to Kiwi Saver. Then upon retirement, the pensioner can structure their fund to pay tax on those gains in the form of CGT (and typically most pensioners don't have working wage income so they would be on the low tax bracket). This is a VERY different model to NZ and i'm not sure how IRD would fit this model?

I can understand why so many in NZ are against CGT. Because they've paid tax on their earnings and then get taxed on the gains when they invest their after tax income. Perhaps it's the fault of NZ's simplistic income tax approach? Like having no exceptions with GST vs Canada has no GST on essential services (doctors / medical / fresh foods /etc), no CGT on principal dwelling home.

The TWG talks of a 'broad base tax' which is different to Canada where you have many exemptions that cater to specific special groups like 1st Nations. IMO a fair tax system should have exemptions because people are not all the same. Some have special high earning abilities, some groups are disadvantaged from birth, and this is the nature of being human and so taxation should be more adaptive than being a 1 size fits all approach.