A tax expert says achieving a fair tax system is hard, but not impossible. 

A UN committee is calling on governments to check their tax policies are being applied proportionally to wealthier individuals. 

It says regressive and ineffective policies could disproportionately affect low-income households, women, and disadvantaged groups. 

Denton Tax Partner Bruce Bernacchi told Kerre Woodham tax can become disproportional when measuring how much tax is paid overall against incomes. 

He says New Zealand sticks out because higher income-earners are earning capital gains but not paying tax on it. 

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