He said while income inequality hadn't changed much in the last 20 years what had changed was wealth inequality and a large driver was property.
Hartwich said people had a perception that inequality was growing and that was not so much about rich people getting richer but the perception that average people were facing higher living costs and that housing was unaffordable.
"We are not going to fix the problem by making people on the rich list poorer - only by making housing more affordable."
Rachael Le Mesurier, chief executive of Oxfam New Zealand, welcomed the rich-list as it helped to open up the debate about wealth inequality.
"Oxfam thinks it is great that we are able to access this information...being able to look at this extreme wealth opens up the debate."
She said Oxfam had been raising concerns about the size of the gap between the rich and poor and the significant impacts it had, particularly at the lower end for some time.
Le Mesurier said in New Zealand the impact of that gap could be seen in a rise in homelessness, lack of decent housing and poorer outcomes for healthcare in certain parts of society, particularly Maori and Pacific Island communities.
But she said there was no silver bullet to fix it.
She pointed to the housing situation in Auckland and that there was no wealth tax to correct the balance for those able to sell a property and make money from it.
Le Mesurier said New Zealand's rich-listers had benefited from the ability to have a free education, access to healthcare and clean water and she expected them to be paying their fair share of taxes in New Zealand.
She said wealth inequality was becoming more of a concern to New Zealand voters and as a result politicians were also talking about it more than ever before.